Hey @Hugs4Hugs I went to Marquette, did classes at UWM, and currently live in Milwaukee.
I personally am not a fan of river west (great for drinks but don't be an idiot. There are good shows/social things to do but I'm not a river west type and I know too many people who have been jumped or had their cars broken into. But yanno, they were doing dumb stuff like walking alone with headphones in or leaving bags/valuables in their car. Plus, it's easy to drift from hipsterville/gentrifying to pretty poor and somewhat dangerous.)
Crime depends on the neighborhood. My friends who went to grad school at UWM lived off of Prospect. East Side is easy to get to/from campus. Areas near the following streets - prospect, Brady, farwell, Ogden - might have good options. I don't know your budget but my friends have good apartments in these areas. Shorewood is also a popular area for UWM students. All of these areas will be a mix of students, young professionals, and older folks. Most busses run to campus and is fairly reliable. If you need to drive there is a satellite parking lot with a school bus like system between UWM and that lot.
I lived in an apartment ran by Ogden when I was at MU and they were useless.
Lmk how how else I can help!