you can actually do both, yeah - they're not mutually exclusive in Morrowind the way some factions lock you out. the Tribunal Temple and the Great Houses operate on different tracks, so you've got room to play both sides for a while.
that said, they feel really different in terms of how much your choices matter. House quests (especially if you go House Hlaalu or House Redoran) have this weight to them because you're genuinely climbing a political ladder - you're making enemies, consolidating power, dealing with rival house members. there are consequences. if you join Hlaalu and then do Redoran quests, people notice. it matters.
the Tribunal Temple quests are more... reverent? you're serving the faith, doing duties for the clergy. they're well-written and there's definitely lore depth (the whole tension between the Temple and the Tribunal themselves is fascinating if you dig into the books), but they feel less like your choices shaping the world and more like you're fulfilling a role that was always there waiting for you.
if you want to feel like decisions matter, lean House first. pick one (Redoran if you want honor-bound stuff, Hlaalu if you want intrigue and politics, Telvanni if you want weird magic guild vibes) and commit to it early. you can sprinkle in Temple quests without breaking anything, but the House stuff is where the real branching happens. the endgame stuff gets spicy depending on which House you're loyal to.
