Don't waste all your time studying opening, lines, and all that nonsense when you're below 2000. Learn the basic tactics (e.g. forks, pins, skewers, etc.) and just look for opportunities for those tactics in that position. Learn basic positional foundations (e.g. if you're down on material don't trade, don't trade active pieces for less active ones). Also do puzzles as well. In essence, just learn all the basic fundamentals and play the game by ear.
Your strategies to improve at chess

I think for your elo this is what I'd concentrate on:
Puzzles for 30 minutes a day
Play long time controls and use as much of your time as possible
Focus on good chess principles - developing your pieces and get castled, rooks on open files
Blunder check before each move and be able to spot your opponents blunders.
Thoroughly review all of your games, especially the losses
My strategy: I create a long term goal for myself and then I create a plan for how to accomplish it. I check back in a month, see what's working, see what isn't. Create a new plan. Lather, rinse, repeat. My current goals are: 1500 rapid by end of year, 1200 blitz, average at least ten rapid games per week, stream at least twice a week. For study, I enter moves in classroom from chess youtubers I admire and study their games. I've picked one opening for white and one for black I specialize in. I do puzzles for about a half hour a day. Thoroughly review all of my games (probably to an extreme that annoys anyone following me on twitch). And lastly, I try to be in a good headspace before going into any games, with some sort of caffeine nearby.
What are some strategies you guys have that have made you better and think more concisely in chess? I'm curious to know and see what you guys do to improve at the game,