It is overwhelming! I've been a few times summer and winter and have only really explored a couple of areas. I'd say both Arabba and Canazei are good bases. I also like Corvara as a town, and you'll find some cheaper accommodation just north of there in the Alta Badia area. For a first winter trip I'd go for Arraba though, it has good access to the Marmolada area, easy road access to the Cortina areas, Tre Cime etc. Unless you have some piste-only skiers with you I'd avoid the "famous" Sella Ronda circuit. It's a great outing for someone who likes pistes but it's a waste of a day for freeriding. If you stay in Arraba and the weather is bad you can find trees to the North towards Corvara, I had a great day there in a storm a few years ago. It seems visitors to the area do not like to ski when it's snowing, so it felt like we had the whole place to ourselves.
I've not stayed in any huts there in winter, but there are dozens and I guess most are open all winter. Given the amount of lift access and day tours I'm not sure you need to worry about huts on a first visit though.
If you've not seen them there are a couple of excellent guide books by a local guide Francesco Tremolada. This is one https://www.versantesud.it/en/shop/freeriding-dolomites-2ed/...
and there's also another volume which is touring specific. They're well worth picking up in local shops (the books are in Italian and English on alternating pages, so they're quite bulky). The best maps are the Tobacco maps, some show ski routes and pistes on them too, which is handy.