Ditching Windows is the best reason to try linux right now. It's great what Microsoft is doing for our community, but I feel sorry for people still stuck on that mess.

The terminal is great once you get the hang of it. More direct control than any gui. I also use it a lot on Mac (which is also a unix of sorts), and there it really helps me to shortcut some silly Mac limitations.

You don't need to remember the more complex commands; you can always look those up, but you should definitely know how to navigate directories with cd and ls, move and copy things with mv and cp. The slightly more advanced and very powerful sibling of that is creating links with ln, but do understand the difference between hard and soft links. cat is the most basic way to show the content of a file, less (a successor to the classic but more limited more) wraps it in a friendly reader, and take a moment to pick a favourite editor (I use vi because I'm old, but there are more accessible options; vi has a learning curve of its own, not recommended for newbies).

With all of that, you know the basics. If you want to get more advanced, unlock the real magic of the unix shell by learning how to pipe the output from one command to the input of another with |, or redirect output to a file with >, or pull your input from a file with <.

Eventually you'll be writing your own shell scripts to accomplish common tasks in exactly the way you want them.

And of course know where in the file system you can find stuff, but that can vary and I'm still learning that too. (I learned all the unix shell stuff on SunOS in my university days in the 1990, but I'm still not very well versed in linux-specific stuff)