Nah his motivations are never dying and ruling the wizarding world, and for wizards to rule over muggles. (Probably because he in turn wants to rule over all of Earth, basically)

My own motivation is "I don't want to ever die lol XD." or at least have a very long lifespan.

You can achieve never dying in the wizarding world as seen by Nicholas Flamel, Tom Riddle thought he achieved that through his horcruxes, if he didn't place them in easy to find locations then he would effectively be immortal.

If Tom's #1 task was never dying, he would have probably just created his horcruxes and just led a normal life. (Assuming he didn't want to keep murdering people)