My first was an all-road type bike, long front-center and long trail, made to be ultra stable. Built on a 26" wheel size (MTB), disc brakes, road-like rear end. Love it. Fillet brazed, stout. Build the type of bike that speaks to you. It'll be your first, and you only get one first. If a rando is your thing, by all means do that. If a hard tail MTB is your thing, do that.