I have only played sekiro from the fromsoftware games but i am pretty sure the souls games follow a similar formula. I like to see the bosses as a performance. You spend time to learn the boss and his moves and the reward is that you can beat him consistently now. The fight becomes a dance where you are reacting to all the attacks of the boss perfectly. To an outsider your performance would seem impossible to pull off but that is only because they don't know that you spent time preparing for it. But beating one boss doesn't help you in beating the other bosses. You have to learn them from the scratch since they have different moves, different combos and different timings. But once you know a boss, you know him forever. You can fight him again after a few months and still perform decently. Only after a few attempts at the fight you would be back to your top form . All because your brain still had the ingredients(The knowledge of the boss' moveset) still stashed somewhere in there. Although from what i have gathered by reading other people's experiences, souls games(which includes your elden ring too) are somewhat less about memorization as compared to sekiro and you can git somewhat gud at the game on a general level. Not sure tho.
Basically just keep fighting and you will beat the boss after 100 attempts is the only real advice. Apart from the that, leveling up your character and getting weapons through grinding is a part of the souls games as well but i can't say anything about it since i have no clue how it exactly works.
All games are worth pirating man. There are so many great games. I am replaying resident evil 2 remake right now and loving it. When i played it for the first time few months back i was so terrified and rightfully so because it was the first real horror game i had ever played. Now i am not so scared.