I would second the recommendation for the Park Hotel Lauren, which is about a block from the rail station and two or three blocks from Walther Platz, at the center of town. A cheaper option but also excellent is the family-owned Hotel Feichter, on the same street as the Lauren though a block closer to Walther Platz.
We stayed at the Feichter https://www.hotelfeichter.it/en/ this month and found it perhaps our favorite hotel in three weeks of travel in Italy, and had drinks and lunch at the Lauren -- it is a classic posh, old-school European hotel though not at all stuffy. It exuded charm and class and struck us as a great place for a splurge.
We found Bolzano itself an unexpected delight -- like many we were there mainly to enjoy the Dolomites -- easily accessible by bus from Bolzano) but found the German/Italian mix of Bolzano (Bozen?) made hanging out in town great fun.