For some reason I feel a little uneasy asking a food question from a "Pukin Dog" ... but here goes: What is Uni? I've had sushi but it was served at room temperature and it was awful. Maybe I need to try it again from a better place.
Uni is the roe (eggs) of sea urchins. It's kind of creamy yellow, with a very soft texture, and an odd flavor. Not everyone like the taste, but if you do, it can be addictive.
As for sushi in general, go to a good sushi bar with someone who like sushi and try a few roll sushi varieties to start with. Some California Roll or something like that. Most people like that pretty well.
Then graduate to other sushi types, trying ones that look interesting to you. You won't like them all.
It's an expensive habit, but really good sushi is some excellent eating. Use the stuff you don't like as catfish bait.
Rule Number 1: Never order Sushi if you don't live by the sea. :-)
Just for future reference.
You do. Sushi is not "something." Sushi is hundreds of things. Cooked shellfish, raw or smoked fish, rolls with veggies, etc. Start with cooked shellfish (maybe a California Roll.) Many people can't get over the thought of raw fish. That's only a part of sushi... (and my favorite part, BTW)