I will be in Florence in June and want to do a weekend in the Dolomites hiking. I will not have a car. What is the best way to get there using train/bus? Once in the Dolomites, what is the best village for a base for day hikes. I'm in my 50's in good physical condition traveling with my college-age son. Not looking for hardcore hiking; looking for fun day hikes. Thank you.
Take the train Florence to Bolzano .
At Bolzano take the bus to Ortisei.
Stay in Ortisei. Go up to Seceda there is some hiking up there not to steep.
I only did this on day trip from Florence.
In addition to Ortisei, I would also consider basing yourself in Seis or Castelrotto. In all three of those towns, you can easily reach the Alpe di Siusi plateau, which is a wonderful destination for day hikes in the Dolomites. To reach the towns from the Bolzano train station, check to see if your accommodation offers a free transfer or you can find a bus route via Suedtirolmobil. Have a great trip!
Ortisei has 2 cable cars and a funicular in town, more than enough for a few hikes. Kastelruth is the recommendation in the RS book but it doesn't have any mountain access in town. Given your short stay it seems easier to stay in the town with the access right there. As your trip gets closer look up the activities offered including guided hikes on the https://www.valgardena-active.com/en website (summer activities probably aren't posted yet). We did several from Ortisei last year and they are free if your hotel is a Val Gardena partner which most are. Keep in mind the weather in the mountains can be anything from the 80's down to snow so you might want to pack to accomodate a reasonable range of possibilities.