Hello.
We can talk about this from differents points of view. In my opinion, even a new player should start studying the game theory. So, if I were you, I'd do exacly this:
1. Get a preflop GTO ranges. If you don't have money to buy them, you can use the pokersnowie preflop advisor for free. It's range is not perfect, but it's close to it.
https://www.pokersnowie.com/preflop-advisor.html
2. Get a postflop framework to think about the game. For this, I'd recommend the Postflop Engine. It's only $7, and it's very solid. It's not GTO per se, but it's a very solid heuristic.
https://upswingpoker.com/the-postflop-gameplan/
Well, with these two points, you'll have a solid preflop and postflop game. After that, you'll have to get the details better. For this, I'd suggest a solver. The GTO+ solver is very good, and it's cheap ($75). It's a little bit intimidating when we start using it, but don't worry, you'll get it after watching some youtube videos.