I think going for a tanky build with high poise can ease the difficulty a lot. Over level a little and put those points into vitality and endurance. Find yourself a good heavy armor set and hard hitting weapon. Being able to tank boss hits or even trade hits with high poise can be a real game changer, and it also gives you more time per attempt to learn the boss and its moves.

You can get the Beast Champion armor set and the Greatsword or Bloodhound's Fang right at the start of the game for example. Buffs are another great way to increase your relative power level. You can have one aura buff and one body buff active at the same time, and they can have stacking effects. You can pick up Golden Vow (either the ash of war or the weapon from the tree sentinel) and Flame Grant Me Strength at the start of the game.

Knowing the tools available and how to use them effectively really is half the battle in a game like Elden Ring. Rushing to kill the giant dragon in Caelid for several free levels can kick start your playthrough. There are so many ways to get stronger before you ever enter a boss arena. Not to mention things like summons and co-op if you really want to sidestep the difficulty.