DUH...Underside of STAIRS!

I'm a total cocktail nerd, so keep this in mind. If you spend any time on Reddit, check out barbattlestations for some ideas. Depending in your budget, I would get a decent undercounter fridge with a small freezer compartment and space to stand up opened bottles. Then a small ice maker either undercounter or countertop. You need to have space to store the countertop model when not in use. Make sure in those cabinets you have a few drawers. This makes it easier to store and access small things like corkscrews, hand juicers, small measuring cups, etc.. I don't know how old you are, but while beer is your focus now you may morph into enjoying wine and cocktails just as much. We were total beer drinkers when we first got married and have now switched out a lot of our beer gear to accommodate new things. You have way more space than we had so it should be easy to have a versatile set up from the start.

Airbnb may not have any rules but your insurance and town have very specific rules about what can safely be used for sleeping in. Proper ceiling height you have but a bed room, due to fire safety concerns, must have two separate forms of egress. If there is a fire and a paying guest was injured or heaven forbid died due to no safe egress your insurance would not cover your liability costs or you could be charged with neglect manslaughter.

Consider moving your dining furniture into this empty...makes serving and cleaning up that much easier and then use the newly available room for a library or office or craft room or whatever you may need or want.