best way to Learn openings


Use chessable. Tons of free courses and helpful for introducing mainline ideas and fundamentals. You can also just poke around in the lichess database for new moves that are interesting.

Learning the purpose behind moves is much more important than memorizing. Usually the purpose is connected to chess opening principles, so at the lower ratings (especially 1200 or lower rating), you can get by on just learning chess opening principles and putting little to no emphasis on memorizing opening theory.
It isn't that they go against each other (because they don't), it is just that those very chess opening principles are the foundation for those mainlines worth memorizing in the future. It makes sense to learn those basics and the "why" behind the moves first:
https://www.chess.com/blog/KeSetoKaiba/opening-principles-again

Chess Openings Resources for Beginners and Beyond...
https://www.chess.com/blog/RussBell/openings-resources-for-beginners-and-beyond
https://www.chess.com/blog/RussBell

Just memorize moves. Dont worry about that pesky "why" behind each move.
ok so I have this line memorized by heart for black
e4 e5 Qh5 Nf6 Bc6 Nc6 Qxf7# wait what how did I lose I remembered everything :.(