Firstly listen to
@Caddchef because that guy can paint him some motherfuckin' Orks! Filthy heretical greenskins aside, in my opinion, mediocre paints are fine, what you need are GOOD brushes. Don't buy GWs own brushes, they're overpriced. I recommend a Windsor Newton Size 000 Kolinsky Sable for fine detail and then a decent set of sable brushes for everything else. GW spray undercoats are, again in my opinion, a must. Corax White spray is a gorgeous undercoat to work from, as is Chaos Black. Read guides, google shit, don't be afraid to fuck up and remember, if you make a mess of a mini, it's not the end of the world, dump it in dettol disinfectant (MUST be normal brown Dettol) and the paint comes right off. Post your work here, you will get helpful feedback.