What works for your story?

With 1 and 2, the issue of communication isn't important, as the story's more about other things - the adventure, or the sense of wonder exploration. Same with 4, to a degree (so long as your world has sufficient magic to allow it.)

With 3, you might create more of a stranger-in-a-strange-land sense of alienation and "otherness," plus you can get some nice characterization, world building, and plot elements in as the MC struggles to learn the language. The struggle can be an integral part of the story.

None of these approaches are inherently wrong, they just fit with different styles and different stories.

Given the overall tone of the post, though, I get the impression you don't like the handwaving or "translation convention," and want to have the MC have to learn the language, but aren't sure if portal fantasy readers want to deal with the language issue. It has been done before, so it's perfectly legitimate and a fine way to write a portal fantasy, and I don't think anyone would stop reading a portal fantasy just because the MC can't immediately communicate with the locals. (If they do, they weren't going to read your story anyway, so don't worry about them and write for the ones who do read it.)