Are you also getting new rear wheels? The 7 speed hub is probably not wide enough for anything other than 7 speed. You might need a new rear wheel.
Does the sora have a front derailleur? Are there suitable mounts for it on the frame? (As the triban does not have a front derailleur).
If you made sure everything is compatible, it can be done, even by beginners. Just calculate extra time for watching YouTube vids 8-)