Star Trek would be the best universe to get isekai'd into, because they'd be nice and actually pretty understanding.

"I'm from another dimension or something and I don't know how I got here!"

O'Brien: "...that can happen, we'll run some scans on you or whatever, maybe we can find a weird field and reverse it to send you home?"

"And in the other universe, everything here is a work of fiction!"

Sisko: "That actually happened to me once..."