You will have more than everything you need in your first shipment. The only thing I can think you need is alcohol wipes to prep for injections, if you don't already have them.
For what it's worth, here's what I use from my assortment of syringes and needles:
Insulin Pins - these are tiny, but I use them for HCG injections in the pecs and/or delts and they work great.
I also received 23g syringes and 18g needles. I put the 18g needles on the syringe to draw my Test and then inject with the 23g needle.
Everyone probably does it differently, but this is what I have found to be the easiest for me.