I've wanted to play both for a while now but which do yo think i should get first. The only other souls games i have played are Elden ring and bloodborne, i don't think I've played anything like BG 3 before though. I know both are masterpieces so it just makes it really hard to decide on which game to buy (other games i like are persona 3+4, Witcher 3, hitman WOA + blood money, the metro games and DBH)
What did you think of Elden Ring and Bloodborne? DS3 and Elden Ring are very similar in terms of combat and story telling (DS3 being somewhat more linear and having less options when it comes to combat). BG3 is a very different type of game and while I think you'd probably like the story aspect of it more based on what you've said you liked, I don't know about the gameplay.
If you enjoy soulsbornes for the combat and excitement, stick with dark souls. If you like soulsbornes for the reactive worlds, interesting level design, and versatility of builds, then give BG3 a shot. (Then play DS)
BG3 is GOAT level