How do you say: "How do I get to the Louvre by subway?"

How do you say "I am learning about X/I have been learning about X" in French?

How do you say "I know there is a form for that, but I can not remember the name" in French? je sais il y a un formulaire pour ça, mais je ne ... pas le nom?

Why is "forgotten most of it" = oublié la plupart de celui-ci? what is the context of usage for celui-ci? Is it different to say I have eaten most of it. I slept through most of it. I remembered most of it.

May I... pattern in French. How do you form a request pattern like May I... like May I eat this? in French.

How do you say "This is difficult to explain in French"

J'ai ce rechercher How do you say "I have researched this" in French? Can ce be used in the direct object position like J'ai te regarder. Can I say J'ai ça rechercher

apprendre vs apprendre à my french textbook says that apprendre means to teach and apprendre à means to learn. This is really confusing. How do you disambiguate between I would like to learn french vs I would like to teach french?

Does "je voudrais ranger ce chambre" make sense? Google kept suggesting sa instead of ce.