Endgames are important to learn but you really only need to know the overkill mates (two queens, two rooks, queen and rook, king and queen vs king, king and rook vs king), and be able to do them in 30 sec or less. That way you can convert in severe time pressure. Also learn the principles of the endgame. This will help you in any endgame you get into. You can learn the basics of the king and pawn endgames if you want as once you get to 1000 you will need to learn that, but it is not necessary at this point in time. This is how stronger players convert one pawn advantages into wins.
Learn the very basics of strategy can be useful, but really learning beyond what they are and the basics of evaluating a position are all that is necessary. You should spend the least amount of time on this right now.
Tactics is what you should focus on the most. Doing lots of puzzles is what you will do the most of. Also learn how to blunder check. These two things are what will give you the best return on your time. Not giving away pieces or blundering 1 move tactics will increase your rating the lost right now.
Hope this helps
As in the title im currently at 850 , but generally im on the border of 800-825 and rarely break this. I played casual chess as a kid and a few months back i re-started chess on chess.com . I dont know many standard opening , i just use the 2 which work for me
I feel the reasons for this are :1) blunders , yes i sometimes make blunders tho im getting better at it . 2)lack of tactical knowledge
Ive seen forums and seen varying advice , some say reading chess books , some say go for puzzle books , some to watch videos and learn or just read about various openings and endgames. Im confused , what should i do?