Yes.
It’s the same with all wine, the main variables are vintage, producer, grape and geography. If you want to get a handle on any one of those variables, you need to hold everything else constant and vary the others.
It can be daunting because there is so much out there to drink/explore, but you have to get started somewhere! Things go more quickly if you can assemble a group who is interested in opening lots of bottles, where you can vary a few dimensions.
I agree that you might get a quicker sense of terroir from the dry wines, because sugar has a way of covering things. But you can also find terroir differences in the off-dry wines.
I wouldn’t get too hung up on specific producer recommendations, people are just going to start listing their favorite wines, which may or may not be yours, and may or may not be easily available to you.
As far as “understanding” what you’re drinking, I think many of us believe that comes best when you visit the region, speak with producers, understand the culture, etc. But that can take time.
In the short run, since you’re on the East Coast, try to attend one of @Robert_Dentice 's fabulous Riesling Study events!
And I assume you’ve read this thread