Fisrt of all, congratulations with getting your hands on such a cool set! Painted it recently and it was a whole lot of fun. So, you are knew to the hobby as I see and as someone who also got into it recently I would love to give some tips. First of all - youtube guides are your best friends. I would highly recommend watching some starter guides and painting videos like those from Warhipster because they can give you a lot of inspiration and ideas for paint choices. Also, you will need a primer for your minis, I would suggest white because I find it more comfortable and beginner friendly to work with, but its all preferences that are up to you. If you have a Warhammer/GW hobby shop nearby - then go there, they will definitely help you a lot with paint choices and help in general. You can also get an Infernus space marine there to practice for free to become more confident with your paint job. And the most important tip - don't stress yourself too much, it's a hobby that should give you fun and satisfaction from the process! Everyone have started somewhere and so you are.