Staying on the Steep Part...of the learning curve

Rookie here! Please help me get out the gate with the right Zwift set up.

I'm a long time MTBer/gravel cyclist...and a long time hater of indoor exercise. After complaining about my schedule and how little riding I've been able to do this year, my brother scolded me for not embracing the new exercise bikes. I spent some time this morning learning the basics and I'm ready to jump in. But I don't want to dive down this rabbit hole like I do with every other purchase I make.

What's a good set up? I have other family members who might use it, so the Wahoo Zwift Kickr Core 2 seems right. What else should I think about? If I was willing to spend more, what would add value? My sense is that there's always add ons, some are good, some less so. How big a screen necessary? I'm going to be doing this in an unheated/uncooled garage. Is this stupid?

I'm still going to want to head up into the hills when I've got three or more hours to ride, but that's not happening much these days. In between, I want to stay fit and possibly have some fun. I don't want to buy a set up and then find out after a month or two that I should have done something different. I've found in cycling, buy once/cry once is cheaper than having to buy twice.

Any advice would be appreciated! Thanks.