Only be done by taking some form of lessons by someone capable. At the very least, you would need to watch a lot of youtube videos about setup, backswing, downswing, and be able to film yourself and figure out where you are going wrong. My advice would be to find one online youtube instructor person and follow most of his advice. Switching around from person to person can be confusing and you can get conflicting info. One channel I really like is Giles Gill golf on YT. Start with your setup and be willing to completely change. Most golfers don't even start with the basics of setup right and it makes everything so much harder to be consistent. If you have bad technique, it doesn't matter how often you are practicing or swinging, you will always be inconsistent. To get good at golf you need to have a repeatable swing with predictable ball flight.

The skillest app is a great thing if you want to do virtual lessons. They are nice because typically in a real in-person lesson, the instructor will give you one or two things to work on, and then the rest of your lesson is you hitting balls and them just watching. This cuts out that wasted time. There are some good instructors on there for reasonable prices.

How often are you playing? If you aren't at least hitting balls a few times a week you won't improve. Even if it's just a backyard net set up, it makes a huge difference to be able to perfect your swing.

Do you know where you are losing the most strokes? A system like Arccos tells you what parts of your game are lacking the most. Usually it is not what people would have guessed on their own.