Play a lot, analyze your games, and primarily study tactics. Your knowledge of openings, endgame, middlegame, etc. will come from analyzing your games and going over grandmaster games. Only study one of those specific topics if it is clear you are specifically losing because of that topic.
Source: https://www.gautamnarula.com/how-to-get-good-at-chess-fast/
As a coach, I can help you with any part of that process. Good luck! 
Improving Your Chess - Resources for Beginners and Beyond.....
https://www.chess.com/blog/RussBell/improving-your-chess-resources-for-beginners-and-beyond
https://www.chess.com/blog/RussBell
Dear Dalta94,
I am a certified, full-time chess coach, so I hope I can help you. 
Everybody is different, so that's why there isn't only one general way to learn. First of all, you have to discover your biggest weaknesses in the game and start working on them. The most effective way for that is analyzing your own games. Of course, if you are a beginner, you can't do it efficiently because you don't know too much about the game yet. There is a built-in engine on chess.com which can show you if a move is good or bad but the only problem is that it can't explain to you the plans, ideas behind the moves, so you won't know why it is so good or bad.
You can learn from books or Youtube channels as well, and maybe you can find a lot of useful information there but these sources are mostly general things and not personalized at all. That's why you need a good coach sooner or later if you really want to be better at chess. A good coach can help you with identifying your biggest weaknesses and explain everything, so you can leave your mistakes behind you. Of course, you won't apply everything immediately, this is a learning process (like learning languages), but if you are persistent and enthusiastic, you will achieve your goals.
In my opinion, chess has 4 main territories (openings, strategies, tactics/combinations and endgames). If you want to improve efficiently, you should improve all of these skills almost at the same time. That's what my training program is based on. My students really like it because the lessons are not boring (because we talk about more than one areas within one lesson) and they feel the improvement on the longer run. Of course, there are always ups and downs but this is completely normal in everyone's career.
I hope this is helpful for you. Good luck with your games!
I’ve recently got back into chess and I’m wondering what’s the best way to improve my gameplay. I’m trying to learn the Giuoco Piano opening as that’s the one I’m most comfortable playing by watching YouTube videos. I’m wondering if there is any good YouTube videos for me to watch that can eventually help me with my middle game and endgame. I struggle a lot through the middle game through blunders which is something I am trying to work on, but any tips to help me improve my ELO would be greatly appreciated.
Many Thanks