As for me, playing as a nomad, i tent to not search for strongholds but instead try to fill my enderchest with as much stuff as possible i call "treasure". Can be anything, realy. From discs to trident or even mycelium. Usually i tent to die while clearing mansions or bastions. Piglin Brutes & Evokers defenetly aren't easy pie for hardcore mode.
Also illager rades are full out wars when playing hardcore. I suggest to prepare as much beacons as possible for the raid within the desired village. Also watch the time before you start the raid! You should sleep first & then enter your prepared village. Otherwise you risk an all out war including mobs spawning during night time.
If you want to do a lvl 5 raid on hardcore you should at least have a stack of golden apples as well as full enchantet gear (diamond or netherite). A beacon row with positve combat effects would increse your chances of succeding dramatically.
Also watch out for drowneds. They can tear you appart in no time, even when you have a shield. These guys are clearly overpowered...
Depending your enchants, focuse on 3 tines protection IV, one with projectile protection IV.
That's the best protection for player vs mob.
Unless your playing some crazy multiplayer with ppl trying to blast you with endcrystals, you shouldn't need blast protection.
Fire protection is next to useless imo since you can nullify firedamage by using potions.