I've been painting scale models and figures for about 5 years now, and for what you've listed, here are my tips:
Don't buy paint sets of any kind. Most of them contain paints that you'll use once in a blue moon. Off the top of my head, for star wars stuff, you won't need a lot of greens, so owning one good single pigment green and mixing paints to get other tones is plenty.
Most wanted brush set is fine. Brushes are consumables in this hobby, so expect them to become less usable over time. Having this set is fine, and then you can replace the brushes you use the most as time goes on.
Matte white primer. I guess this is fine, but for speedpaints/contrast paints, a really easy way to get results that look like you put more work into them than you did is through the "slap chop" method.
Matte varnish. I've never really had problems with having to varnish my miniatures but I won't advise you against it. My favorite matte varnish is Vallejo ultra matte (72653) which I use to make gloss stuff matte instead.
Project paint station. Organizing your hobby space can be important, I personally use products from hobbyzone.pl.
Washes are a great way to bring a model to the next level. I recommend getting a black, brown, and a sepia wash.
A couple more words of advice from me:
Buy a bottle of whatever the "medium" (the medium is like the paint without the pigment) is for those speedpaints. Speedpaints (and contrast paints, and every equivalent paint set) have massive variance in saturation and coverage. If you want a more consistent experience, you can use the medium to thin down your more saturated paints. Water might work, but the medium will work.
Get a proper light. An architect's lamp of some kind will do, and get a light bulb with 4000K rating. This will give you a natural light so you have a good idea of what the miniature really looks like, and will keep you from straining your eyes.
Your next big upgrade when you start moving away from speedpaints is going to be a wet palette. I can not stress how much value this one tool can bring you.
Always keep in mind this is a hobby. If you want to do your hobby, do it. If you don't, don't. Don't feel bad about having too many miniatures in your backlog. If the army is getting boring to paint, just paint something else. It's ok to paint a random lizard, or superhero, or dog, or whatever. It's ok to paint for a week straight, and it's ok to not paint for 3 months.
Your minis don't have to look like the crazy stuff you see on pinterest. It's fine to get inspiration from them, but don't let them demoralize you. Keep in mind some people have as much as 20 years head start on you. Some people spend hundreds of hours on a single miniature. Some people are army painters, and some are display painters. It's not a contest unless you sign up for it.
Engage in the hobby with other people. Take any chance you have to visit your local hobby store, post your painted minis on lemmy, etc.