Easy enough brother. I would get 3cc barrels. Then a 20g pin to draw and a 23-25g pin to inject. For injections, you want to use between a 1 in to 1.5 in pin for glutes. 1in for quads and delts. These are the common areas to get used to injecting. Heres a great write up over at juiced muscle that will walk you through step by step. 

http://juicedmuscle.com/showthread.php?49-A-Guide-to-Safe-Injection-Technique