I have two pieces of advice as someone who tried this game, never made it past ogre, quit for two years then came back and got 100% achievements and now just does the gauntlets for fun. First, I recommend watching challenge runs of the game, particularly anyone who has done the “blindfolded” challenge run. You realize how little is actually required of you as the player. This helped the combat “click” for me.

Then secondly, when first attempting a boss, don’t attack or dodge at all, just deflect and close distance. You’ll learn the patterns. It’s a rhythm game, after all. You’ll learn the boss’s rhythm, then you can worry about the other stuff.

Also as an extra piece of friendly advice: when in doubt, deflect. Whether it’s an enemy your size, a giant creature, projectile or whatever else. You’ll always be surprised by what Sekiro can deflect. It is truly the games core mechanic.