beginner hobbyist asking some basic questions for airbrushing and thinning and stuff

[peak echo]

So im interested in building tamiya 1/24 car model kit and I try to learn as i go but im unable to find a concrete answer to my questions so here's my questions:
(Do note that all my color are all mr color stuff)

1. i have mr color thinner and mr color 1500 primer gray, what's a good ratio for primer and thinner?
2. is it okay to premix paint or its only allowed for primer? i heard premix paint color is not a good idea
3. I have mr color super clear III UV cut, is 1:1 ratio for thinning is a bad idea?
4. what's the cheap alternative to cleaning your airbrush?

[glacial moon]

1, 1:1 ratio, adjust as needed. I used generic lacquer thinner with mr surface 1000.
Better to find a jar that's already the color you want. Custom color mixing is pro level people using lacquer paint with limited color availability.
3. Adding thinner to gloss paint usually ends bad in my experience. i prefer airbrush ready primer and clear .

Always clean your air brush or be ready to buy new air brushes often. Cheap cleaning solutions are isopropyl, or Windex, or 'fantastik' all purpose cleaner (benzalkonium chloride active ingredient), a jar of butoxy ethanol to make your own acrylic thinner (high risk not recommended), bulk mineral spirits and lacquer thinner depending on what your spraying also cheap cleaning solutions

Since you are using Mr color, hardware store lacquer thinner will work for cleaning your air brush