Heh... now things are starting to turn into a mushroom cloud and your head is spinning on a pivot. Slow down and take it slow with what product you should get, the best process (decanting for one), lacquer, enamel, acrylic, etc...
Granted, this is all new to you. Everybody has given you lots of different opinions and it shouldn’t be complicated for you to figure out what’s best for you and your budget. Start off with the basics. Try something new later on your next build.
I go the simple route for primer Rustoleum brand primer in a rattle can. I’ve got in grey and white. Both are wet and dry sandable and goes down smooth.
I have a wide vareity of paints in my stash... Testors Model Master enamel and acrylics (most of my enamels were from my teen years and still good condition), Tamiya, Gunze, LifeColor, Aeromaster, a few PollyScale bottles, a few Humbrol enamels, Mission Model acrylicswhich I’m planning on adding more colors o my collection to replace some of the enamels. I’ve got my eye on a few AK Real Colors Im looking to add to my paint stash.