Stuck At 1400

Try Tennis

Just keep playing
Watch youtube videos about "basic chess concepts you should know" and common patterns, etc

Start practicing tactics, maybe start engaging yourself in a lot of tournaments, if you're not already, and try reading some books if you have some or buy one. My recommended book is winning chess tactics.

Maybe even try OTB play if you have the time

just doing puzzles doesn't help you with openings...but it's your choice

Attempt to play longer games to establish where your game needs improvements. 20/30/60 minute timers instead of short bullet or blitz games. You'll learn more not only about your game, but the game in general with so much extra time to think about all the possible outcomes of your opponents and your moves.