MVVM is a pattern that lets the view talk to a view model. The view model is responsible for talking to a domain model or facade of a domain model. The communication in MVVM is very much a one-way street. The view model never talks to a view, nor does the model ever talk to a view model. There are other patterns used with WPF and other XAML based frameworks, like Commanding, but they are not specific to the MVVM pattern itself.
MVC is similar to MVVM, as the view talks to a controller and a controller talks to a domain model or facade. The difference is that unlike MVVM's View Model, the MVC controller is bi-directional. The controller can talk to the view, along with letting the view interact with it.
This is of course assuming that everyone writes their code following the patterns strictly. You will find that's not the case; the rules are always bent.
From a career perspective, MVC will probably be the better choice. I personally enjoy writing MVVM based applications, so I stick to that as a career. My advice to you would be to try the two technologies out and pick the one you enjoy. The money will come with experience, don't let money drive your career path. More often than not you end up someplace that you don't like, but making good money. Go work on technology you like, even if it's a little bit less annually. Your health and family will appreciate it.