Diablo 3 today is a different game from that which was released about four or five years ago. I gave myself a few goals, and revised them along the way.
I achieved two of the major ones this week and last week. I made Paragon level 800 last night and Greater Rift level 70 last week.
Now, the final goal would be to put every single power into Kanai's Cube. This would depend on a lot of luck.
I have a minor one of getting higher levels for my legendary gems.