Not too much in terms of thrills here, but walking around the world showcase is fun. The rides are not as important here I think. I suggest embracing the utopic-retro-futurism vibe to best enjoy EPCOT.
Frozen is actually a pretty fun little dark water ride. Shortest line is at night since it’s a lot of kids during the day, and EPCOT usually stays open the latest.
The area outside the back entrance near the UK pavilion has some nice stuff outside the park. That’s also where you enter and exit to use the skyliner gondola (great for getting between EPCOT and Hollywood Studios).