Personally, I don't really think you need makeup. Your skin looks good to me

Yes, there's scars, but I see that on so many guys.
But if you do want to wear makeup...
Primer: A silicone-based primer could be useful to help 'fill in' your scars underneath the makeup. Primer is essentially used as a 'canvas' for the rest of the makeup, making it last longer.
Concealer: Concealer is usually put on before foundation, and covers smaller spots of pigmentation the best. You can use it on PIH and scars, active blemishes, etc. I recommend Makeup For Ever Full Cover
Foundation: Foundation is usually for evening out your overall skin tone. You don't want to pack on the foundation really thick, so use concealer to hide your spots/scars and foundation to even everything out, make it look more natural. If you want to use powder foundation, buy a big, wide kabuki brush and just dust it onto your face in a circular motion. I use MAC Studio Fix, but a lot of people complain about that clogging their pores, so you could try something more natural like Bare Minerals.
Less is often more, and blending is extremely important. Blend the concealer as much as you can and only dust the foundation on. Otherwise people will clearly be able to tell you're wearing makeup. Youtube tutorials on this will probably also help you.