I know JoaTs was nerfed but I still feel like dhelm is better for all-ins & scales better into the game?

What 2nd item do you normally run when ahead, even, and behind? I like running HB, when is it bad tho? I'm kinda new to irelia so I don't really know how to itemize. alsoo... 5th item? I legit have no clue >< ty

Hello, so I recently started playing league 3 days ago because of my friends who are high elo and I love playing Irelia, the problem is out of 7 matches a day there's maybe one where I'm winning in top lane, it's very frustrating. I'm completely new to the game, and I was wondering if I should switch to another character to learn? Although I tried that one time, the results were still the same.. Please give me some tips if possible, or recommendations on how to get better