to start airsofting first find a group of people already in the sport. borrow a gun and try it out. if you like it maybe its time to invest your money in a gun. pick a gun similar to the one you borrowed.make sure it does not cost $100+ as you are a beginner and still haven't learned proper maintenance. buy the gun and enjoy it (it might not last to long :)
list of terms:
AEG: an AEG is an electric gun with full auto capacity (I suggest this for CQB. cheap to expensive)
spring: a spring gun is powered by a spring and therefore needs to be cocked for each shot (for snipers and pistols but cheap)
Gas: gas guns are powered by either co2, green gas, or blue gas most commonly. (these can be very expensive though and are not usually permitted in CQB due to there high power)
CQB: Close quarters combat/battle
Fps: feet per second (the velocity of the BB as it fires out of a gun) higher end guns will reach 500+ fps, AEGs will tend to be from about 300 to 400 fps, spring guns are from 100 to 500 fps.