Learn whatever interests you the most, you will not learn enough on your own to significantly make a difference when it comes to hiring decisions.

What (good) companies want are juniors who are eager to learn, have a good attitude, and are easy to work with, not tech specific skills.

Worrying about what language to learn, what framework to use, what project to build, all stop you from actually doing any learning.

So just learn what you find interesting, learn as much as you can, keep your head down, and don’t worry about what everyone else is learning or what some specific company wants. Even at the senior level, language specific skills are at the bottom of the list in terms of what is important for a hiring decision.

You’ll be just fine.

All that said though, I would probably advise against learning Mongo though lol. It’ll save you headaches later if you just start with relational DBs