that depends on you
both games are good in their unique way.
poe2 isn't fully complete yet nor real polished but it is allready really enjoyable and kind of hooks you in the endgame if you play it the first time.
if you are more into longer thougthfull fights, graphics and story/lore things
poe1 is complete, they do good balance changes there seasonal so the meta shifts a bit everytime
its more of the competetive, rush and zooming playstyle and the full spectrum of whats in there could be a bit overwhelming if you play it the first time
but the endgame is more settled so it is better to compete.