If you want to improve a lot
1) Pick one opening as white and one as black. Do some tutorial videos and make sure you can get 6-10 moves into your game without making a mistake.
2) You need to work on your board vision. Puzzles are really good for this and you need less time to play puzzles than you do games. When you do the puzzles go SLOWLY. Try to figure out the answer before moving pieces. Give yourself a full minute of looking before just "trying" something or looking at hints. Then if you fail, make sure you work it to a conclusion. Look back and understand what you were supposed to notice in the original position.
3) If you are blundering pieces, before you place a piece, just look down the vertical/horizontal lines and make sure there isn't a R or Q there. Look down the diagonals for a bishop. Then check for any nearby Ns who can hit that square. As you get better, you will want to look for possible discovered attacks when you look down the diagonals and rows/files.
4) Try to arrange your pieces so that you aren't floating something out into open space unprotected without at least having plans to protect it (or continue an attack). Your ELO will go up a lot if you just make your opponent work for the pieces that they take.
5) Just focus on the basics. Fight for control of the center. Focus on developing your pieces. Castle by move 10.
If you just do some of the above you can go up 100-200 ELO points.
I noticed there are a couple people above 2000 ELO giving advice. Everything they say is correct, but you don't need to do all of that to improve and some of it seemed a bit advanced for where you are now. I'm not a golfer, but I once took some lessons and my instructor told me to focus on one swing thought at a time. It's good advice. Look at where you are making mistakes and focus on that. (BTW, the lesson on chess.com have some good topics and integrate practice, so that would be another way to do that.)
Que es idk??????