can someone help me get good at chess?

Do you know ladder mate? king rook mate?

those are very helpful

Ok, no matter what your rating is, progress comes from balancing the following elements: tactics, endgames, positional understanding, calculation, and game review. At a 400 ELO rating, I'd recommend focusing on stopping hanging pieces, learn basic checkmates, understand opening principles. Regarding endgames, master these 5 first: K+Q vs. K; K+R vs. K; K+P vs. K; opposition rule (K vs. K); basic Rook endgame principles (active King, etc.). As for openings, learn principles, not moves (control center, develop pieces, castle early, connect rooks, etc.). As for tactics, use Lichess puzzles or Chess dotcom "puzzle rush" (Starter). Aim for 5-10 puzzles/day with analysis. Finally, use Lichess "Learn" module or Chess dotcom "Lessons" for guided practice. Feel free to ask if you have any other questions. Ciao

At this level, memorizing openings isn't really necessary. You should focus more on endgames and stick to playing e4 for your openings. You'll see your chess improve instantly! Feel free to send me a message !