A little more info, maybe?
Rifle? Handgun? Target? Action shooting? What gun do you now own?
Go here and read:
http://www.thehighroad.org/showthread.php?t=236788
Balance the type of competition you're interested in against:
- what equipment you already have & what you'd need to get
- your budget (the cost to get any other equipment you'd need & the cost of practice & competition itself).
- what's available in your area.