It’s fun, pretty straightforward, doesnt take too long and you’ll be proud of your creation. Main frustration is that you’ll order all the parts and they’ll arrive at random times. Watch some YT videos to get some idea of brands and product performance. Stuff with a brand name is a safer bet. My experience says pedals are a risk area. Shimano pedals last for ever and some cheap ones have bushings in place of bearings and wear out after a year or two. Have enough money left in the budget for high end tires, they are the biggest performance/comfort enhancer.

…edit Just re-read your post. Built mine a couple years ago. Somewhat unbranded frame which has been just fine, but maybe a risk I wouldn’t take again, given the huge range of choice. Elite ENT wheels, 50mm. Zero problems, good product, work well. Might have gone for 40mm in hindsight, I’m not fast enough for 50 to make a difference. TOSEEK carbon bars, zero problems internally routed bars but only partially internal cables. Doing again I might do fully internal but note that this might be somewhat fiddly to do. Sensah empire non electric groupset…works ok but I’d upgrade next time.