Your rating is fairly high for what i had in mind, but if you think you lack fundamental understanding, then i might be able to help. I offered some help for just that a few days ago, if you’re interested check it out here Offering Battlegrounds help to beginners (too lazy to rewrite all that).
I think watching high level players as suggested is a great alternative, but if your time is spend well can be very hit or miss. For one as they may not explain their plays(or not in a way that helps), and on the other hand as you may missinterpret plays, which could harm more than anything. This gets only worse if you lack basics. Still, i think that’s a good choice too as long as you don’t sabotage yourself, and find someone who explains turns properly.