How can i improve my midgame?

Hello

Im relatively new to chess, so of course i watched a view chess videos on how to improve. I've decided to Play the Ruy Lopez opening as most say ist pretty good, but every time, I'm done with the main structure i dont really know on what to do and just keep blundering/loosing all my important pieces in the midgame. Does anyone have any tips on how to stop that from happening and what to do instead?

Try to gain space and the center, who ever has both will dominate, and get knights on outposts, really powerful tools.

Ruy Lopez is not a good idea, it has over 500 lines.

Murphy Defense, Stheinz Defense, Spanish Countergambit, Main Line, etc...

try Sicilian Alapin, or Old Sicilian, or even Godiva?

Or Scandinavian, you need a little practice with this one tho

def practice the italian lines, they can be tricky

Develop pieces, control the center, and castle. In the Ruy Lopez, look for plans: d4/f4 breaks, knight maneuvers (Nd2–f1–g3), and attacks. Check for threats before moving. Train tactics to avoid blunders!

Ruy Lopez is not a good idea, too many lines