Lived there for the last four years, downtown. All the good things that people said are true. And, in two weeks once you've done then all, you will realize you live in a small, boring city filled with desperate violent people and a completely flat economy. Oh but wait, a new casino is coming. That will help, right?
Some real advice. Don't park your car on the street overnight, and don't leave anything valuable in it ever. Don't walk around alone at night. Get an alarm system for your house or apartment and use it. Stay away from the strip clubs. If you drive on the Parkway between baltimore and dc, BE Careful. It is one of the worst roads in the country when it comes to accidents. People drive like maniacs there.
Check out the surrounding cities, some cool stuff outside of Baltimore. The Harris teeter is a decent grocery store, plus you can do online ordering with curbside pickup. The wegmans is better but it's a bit of a hike.
Oh also get the fuck out of the city when the grand prix comes to town. It's hell.
Finally, don't try and commute from Baltimore to dc. It's not worth it.