Some good chess training websites

There are many chess websites to train you.

For openings:

https://www.chessable.com/

https://www.openingtree.com/

ChessReps.com 

For middle games:

https://www.chessable.com/chess-courses/middlegame/

https://aimchess.com/

For endgame:

https://www.chessable.com/chess-courses/endgame/

https://aimchess.com/

These websites give you practice sessions to improve your games.