1.)Can you handle being shot? This is the most important question because sooner or later you WILL get shot they may bleed, bruise,and will definety raise some welts.
2.)Can you handle shooting people? This is the this is the second most important question half the fun of the game is shooting people and getting them out and if you can't handle shooting people then you'll just sit there until somebody shoots you.
Step 1: Basic History, and Info
How It All Started- The sport of Airsoft started in Japan during the early 1980s. It was illegal to own firearms in Japan but there was a significant interest in them, so a company started producing spring-powered replicas of firearms that fired 6mm, plastic BBs. During the latter part of the 1980s the sport migrated to neighboring countries such as Hong Kong, Korea, Taiwan, and the Philippines. Airsoft started appearing in North America and Europe during the middle of the 1990's.
Now that you know a little backround you should know the 3 types of airsoft it will help you figure out the type you want and make it easier when you buy it at a store.
Spring Airsoft- First, spring-powered Airsoft gun, the perfect entry level choice. Spring-cocking guns are true to their name in that you cock the spring first, and then fire. Cock spring, fire, cock, fire, cock, fire, etc. These guns are usually magazine fed and semi-automatic, but they must be hand-cocked after every shot. This system is very cost-effective, and the guns are surprisingly sturdy. Every Airsofter, in his lifetime, has owned at least one spring-powered gun, either a pistol or a rifle. Due to it's relatively cheap price-range, this is usually the gun of choice for the person just starting to play airsoft. A spring-powered handgun can be purchased for as little as $20.
Gas Airsoft- Another popular type of an Airsoft gun is the gas-powered. While there are several types of gas-powered airsoft guns, the most popular are the Gas-Blowback guns (GBBs). The GBB allows a realistic, semi-automatic firing of the gun by employing either an on-board, or magazine-stored gas storage system. Basically, the same compressed air that propels the BB out of the bore is harnessed to cycle the slide back (hence: blowback). This creates the realistic "recoil" by cycling the slide/upper receiver back-and-forth while firing the gun. This system gives the hand-held gun the capability to empty a magazine as fast as you can pull the trigger, and just as easily reload the gun by inserting a fresh magazine. Needless to say, this feature holds tremendous appeal for the "simulationist".
Electric Airsoft- Lastly are the Automatic Electric Gun. The creation of the AEG is partly responsible for Airsoft's "boom" during the late 1990s. Basically, an AEG is powered by an on-board battery (similar to hobby R/C Cars), which operates a motor that turns gears inside the gun to compress and release a piston, which in turn creates the blast of air needed to propel the 6mm BB through the barrel of the gun. This system allows the gun to efficiently generate the power needed to support the fully-automatic features of most AEGs and the result is a realistic Rate-Of-Fire (ROF) of anywhere from 600 - 900 Rounds-Per-Minute (RPM), once again mimicking the capabilities of real steel firearms. This is the airsoft gun of choice for most skirmish veterans.