They probably can not. Unless you’ve setup your router such that anyone can connect to an ssh instance running on your PC, and then also use a bad password. Public wifi + having something like ssh running + having a bad password.
Your PC probably doesn’t satisfy these requirements (yay!), but some servers might.
So how would a bad actor start a remote session on my Linux pc?
Edited to add, downvoted for trying to learn is a new one for me.
They probably can not. Unless you’ve setup your router such that anyone can connect to an ssh instance running on your PC, and then also use a bad password. Public wifi + having something like ssh running + having a bad password.
Your PC probably doesn’t satisfy these requirements (yay!), but some servers might.
I do run some servers, but use robust passwords.