I have 10 different kinds and types of airsoft guns just so everybody can play if someone doesn't have their own. It's a fun and cheap game to play. To get into the game it can cost as little as $10 for your first gun.
How i play...
I have a variety of high - low end guns. Every round people play, everyone switches to a different gun so everyone has to change their strategy (it does suck when the same person keeps conquering every match with the same gun, i switched this out for balance, fairness, and for a system that promotes learning how to use all guns, and favors those with skill and strategy). Also everyone gets two clips worth of bb's only along with a one hit one kill melee weapon. Everyone needs to get hit 5 times before they die, unless they're melee'd (5hp because i'm usually playing the game with kids, teenagers, and people my age). These requirements have made all game types for airsoft from average to very very fun (it also uses less bb's, and people who ran out of bb's can still be in the game).
For dress, anyone is allowed to wear whatever they want, but it must include goggles and a face mask. Face protection is primary so you don't like shoot out someones eye, get shot in the lip, chin, or have a bb go up your nose. I don't see why you couldn't go into the game with goggles, face protection, any kind of pants, and a jacket. Who cares about all the other kids wearing camo and all this nice stuff. Certain kind of clothing shouldn't be a requirement. Just the necessary equipment to keep people from getting hurt should be the requirement.
Of which case, a pair of work safety goggles or ski goggles goes a long way. And the easiest face mask is a winter beanie pulled down over your heard with a slit big enough for your goggles to fit through (if you put on a hat first, you can get a hat visor and goggles through the slit). No mouth or nose holes, you'll feel sorry for those if you add them. That is effective budget face protection. And of course any clothing you wear, make sure it's nothing heavy and dense. That would slow you down, and make you less aware of the fact if you were getting hit with bb's.
If the people ***** that you don't have the right uniform, then change their minds, it's not a requirement (or at least shouldn't be one).For beginner guns, i have a few recommendations.

This seems real dinky, but it has a decent rate of fire. The range is about 24 feet at 180 fps, it's easy to use, you can reload it fast. The range isn't great, but this sucker is deadly in the right hands. Strategy is to be a pretty ballsy by going to your opponents, or trick them into coming to you. Also a great gun to hunker down with if you're hidden in the bushes. The main point, once you get someone in this guns range of coverage, you will take someone down fast. This gun can also be modified to be more powerful which will extend it's range.

This one is less dinky and is an actual rifle size. It has greater rate of fire, a range of 40 feet at 250 fps. The butt of the gun protrudes and collapses in based on long range and short range combat. The magazine is dinky as it is the scope, and the scope is just a hole that lines up with the sights. The scope does hold 500 bb's (no need to reload), and the scope hole really does help with aiming actually. Newbies really like this gun since it's an all around decent gun to use in airsoft, is easy to use, and performs about how people expect it too. Negative side is it's hopper gravity fed (so many dumbasses couldn't figure out what i meant by gravity fed hopper, they still tried to shoot the gun upside down or pointed straight up in the air, and then i'd need to show them....uuuugh, dumb people are dumb....the word gravity was descriptive enough). But, since no ones shoots guns upside down and that shooting clouds in the sky is dumb, the gravity feed hopper is really a non issue. This gun can also be modified to be more powerful which will extend it's range.
Grab any pistol you want as long as it's 250 fps or up. I grabbed a pistol that does 350 fps, that sucker hurts. I also don't recommend the use of guns that exceed 450 fps. Anything beyond 450 fps, and you might as well be playing the game with a red ryder bb gun that shoots those real metal bb's. 450-90 fps is a good maximum and minimum for power of guns in use. Don't go to expensive, stick with manual spring and all electric airsoft guns. Manual spring you just get some bb's and you can play (i don't care what others say, in the right hands, a manual spring gun can have a decent fire rate, and automatic fire is not what wins all games). All electric you plug in and charge the battery, usually good for one whole day of airsoft before next recharge. There is CO2 powered guns, but more expensive.
I do have others.

This is a decent mid to high end sniper rifle. I cut the flash hider off (it's pointless since it's not a real gun), painted the tip of the gun orange (so people know it's not a real gun), and cut off the butt of the gun (it essentially has a little pistol grip on it) all to cut down on the length of the loooong gun so it can be whipped out fast for short and long range. Shoots clear through aluminum cans, range of 50 feet.

Purely a long range gun. 460 fps, the only gun that exceeds 450 fps by an allowable margin. Long range, can still aim it accurately without a scope. I hated using this one of mine, i let other people go for it. Which means other assholes getting good at shooting me in the trigger finger.

Another high end gun. 400 fps with decent range. Eats through ammo fast on automatic, so i use semi auto a lot (other people using it are content with running out of bb's faster during the match with limited bb's as a requirement). I had a tank top on one day and got sprayed with 5 shots from this gun....and son of a *****! It will tear an aluminum can to pieces in seconds.
Fun game, there's plenty of times where i have the mini uzzi and i'm needing to take down the guy with the p90. Or, i'll have the pistol and that's when the game gets really hard. I'm also considering letting people use nerf guns if they can carry them into the game with the weapon they were switched too. It also helps to have some good arenas to play in. Junk yards, patches of forest, etc.
If these people wont play with you because you don't have a uniform...then i guess shoot one of them and run? Lastly, guns can be had for cheap (you really dont need to invest much money at all for your first time getting into airsoft). Check into my recommendations for cheap guns for noobs to start out with. I recommend that mini uzzi and m4 big time (or have a mini uzzi and cheap pistol weapon combo). The uzzi can be had for like $12, any pistol $12 or cheaper, but i'd spend $15-$20 to get something decent as a fall back side arm in the beginning. Later in life, get that m4 (that crossman m4 is sort of like how comfy, effective, and easy to use the apollo in fs1 was). Then later check out a good sniper rifle. I recommend that m14 since it's a great sniper rifle, and it can be customized to be made smaller. Bb's are cheap (most guns you buy come with a sizable amount of bb's too)!!!! I bet you have clothing that you could wear for this game, a winter beanie you can modify into a face mask, a pair of safety or ski goggles laying around, and $25 or less (if you have the money for it, i would get the crossman m4 first).Go for it starslayer. Clothing is a non issue, and the only funds i see you needing to spend is just on your first gun.