I (29M) grew up in Baltimore County and I loved it. I’ve lived there in various areas up until last year. Lived in the city with my GF for a bit and now we live out in the country. Towson is probably going to be a place of interest for you. It contains Towson U and Goucher so plenty of college age people. Good restaurants, a music venue, a mall, etc. and it’s walkable. North of Towson up through York road is cool (Lutherville, Timonium, Hunt Valley) it’s suburban but lively. Also lots of good food and bars and shopping. Bars like High Tops will have a younger crowd. Also plenty of light rail stops to get to conveniently into the city. East of Towson toward Parkville and White Marsh can become a bit more blue collar. Again tons of great restaurants and convenient shopping. Probably less of a scene for a young twenty something (Das Bierhalle is a popular spot).

Hope this helps. Baltimore County is bigger than t what I described but those are notable mentions. Let me know if you wanna know more about any of that.