The title says it all. What paint are you using for ships and squadrons? I'm preparing to buy some paint to finally start painting but I'm not sure what kind of paints I should buy. Maybe matte color for the hulls, gloss black for fighter canopies and gloss blue for thruster exhausts?

I only use gloss for engines and some canopies as you said. Matte all the way for everything else.

Use Matt paints for everything and if you are really interested in glossing an area, use clear gloss varnish over your paints after spraying with Matt varnish to protect them.

Glossing canopies works well but I'm not sure about engines because Gloss with allow it to be hit with the 'IRL' light sources in the room which may conflict with what you've painted.

Matte paints. Then matte varnish. Then, as someone said, use a little nail polish to gloss up canopies if you need to.

All three.

Paint with matte colors.

Light varnish of satin to protect and give it a look of painted metal (like the sheen you see on modern fighters).

Gloss varnish for canopies or gloss the entire ship for "hotrod" jobs.

Almost all of mine are finished in satin if you go to my thread you'll see lots of examples. My go at tiny spaceships.

From a spray can perspective, satin if you don't have a matte choice works for bases. Your wash will help kill some of the gloss in it.