First off, congrats on making Pro. It is your first real move up, if you ask me.
On the slower greens, like "standard", you actually have to hit it harder than the distance required. On the "fast" and "very fast" greens, you're getting more to the actual distance, on level ground of course.
On faster greens, you have to allow for more break. On "standard" greens, you're almost hitting it through the break because you have to hit it so hard. On the faster greens, you're not going to hit is hard and the slope of the green will have more effect.
I don't have a formula or anything, I've just used my experience to get better.
As for approach shots, when I was still using a starter ball and the starter clubs, I took advantage of the open greens. If I could roll it up to the hole, that was the best way to get it close. If you don't have that opportunity, then you need to be really good with your shots around the green and with long putts.
When I was at your level, par was my goal. Even if I had to lay up on a long par 4, if I could then get it close for a one-putt par, then I was a winner in my mind.
The green dot on the ball is for spin. Push it up for over-spin and down for back-spin. The more over-spin, the lower the ball will fly and will land sooner, but it will roll farther. The more back-spin, the shorter the ball will fly and the less it will roll when it lands, unless you hit a hill or if you're shooting at a target that is much higher than you.
I didn't start spending money on this game until I was almost a Tour Pro. My first purchase was a better golf ball, one with some spin. I started with the low-cost WGT balls, but it was something with some spin potential. It wasn't the best but I was able to learn how to control my approach shots better with back-spin and I could hit more of those protected greens instead of laying up.
I was fortunate to have a couple of good wedges gifted to me at Christmas and I used those to full advantage. It wasn't long after that I was scoring lower and lower and finally made Tour Pro. That's when I finally bought some new clubs. Even then, I only spent about $30 of real money.
Enjoy the journey. It doesn't have to cost you anything, or even an arm and a leg. You can control your success by learning how to play with what you got.
I'll friend you and maybe we can play a few rounds.