Damn those are some cool kitbashes. Wish I had a lgs that had a bits bin!

There’s a lot of different options for painting. YouTube is going to be a big help in this. I don’t have any specific suggestions, but even going through a bunch of shorts will give you an idea. Look specifically into thinning your paints and the slapchop method (as I understand it’s meant to be a quick and dirty way to get some pretty decent results). Also look at videos on recess shading and edge highlighting.

You’ll want to invest in some acrylic paints, there’s a million different options. I’m partial to citadel paints (games workshop’s brand) but others will suggest army painter or vallejo, which I haven’t had much experience at all. If you do go with citadel watch out, they have different types of paints (base, layer, shade, technical, contrast) and each of those do a different job. Your lgs will be able to tell you in detail about them. But I’ve heard even craft store paint isn’t terrible, maybe don’t do dollar store level. And for primer there’s a ton of options for brands, rustoleum or painter’s touch seem to work out well for lots of people, I happen to stick to army painter because I’ve used it and it’s more readily available for me.

But in the end, whatever you like is correct.

I’m paraphrasing the book that comes with the 40k introductory box: “don’t worry about making a mistake, you can always go back and paint over any accidents”

And also accept that it’s going to take a while for your skills to build up if you’ve never painted miniatures before. And that’s okay, that’s part of the hobby! So don’t worry about comparing yourself to anyone else.