1 Think long term.
2 Mainly for self, self and partner, self and partner and friends? Choose one and gear towards that.
3 At parties, people will gather round a bar if you even give them half a centimeter of space to do so, this can be good or bad.
4 Themes......do it well if you want to. Less (theme) is more (function) for me.
5 (Used?) fridge with water and ice is nice, but a sink is a better option if you have limited funds; both are better.
6 Beverages generally require glassware. Get some reasonably inexpensive simple glassware. Don't go fancy.
7 Comfy seating, get some. Unless the bar is next to the workbench in the garage next to the kid's trike, then those stackable
stolen lawn chairs fenced on Craigslist is better.
8 Just realized that you may not have a whole room to dedicate towards this....that changes some of the above.
9 Are you sure you want to do this? If the primary drinking of delicious fermented malt beverages or sumptuous fermented fruit sqeezin''s for you and/or you and yours and one or three parties a year, maybe money is better spent on other things, like decent outdoor furniture, a high quality ice-chest, and a rolling cocktail cart*.
* - About 2 decades ago, we found an antique rolling cocktail cart from an estate sale near my dead racist great aunt's home in a suburb of Sacramento. Tight grain oak, quality castor wheels (if one can say such a thing about castor wheels), minimal signs of use, lots of evidence of cleaning/maintenance and rewaxing. Has expandable leaves on the side, storage area under the top, and now lives as a kitchen-nook companion to the a display cabinet Sweetie-pie got from one of her grannies (the cabinet stores things we rarely use).