Deca injection info

Well the time is here and I need helpfull tips and info. I have 1 amp 200mg deca an 2 amps of 200mg durabolin. Whats the difference between these two? Should I mix these to make 2 doses at 300mg, each with 200dura-100deca? This is my first cycle and I can get deca or durabolin. Im planning to inject every 5-7 days@200-300mg each for 6-8 weeks. What do you guys think? Also I know injection procedures but I havnt actually done it yet? How hard is it to do? and does it hurt? I’ll be using a 22-23ga needle I think, cant remember which. Thanks Dave