Will Sensei tutorials work even if I do not use Sensei, especially when rigging models. I notice that Sensei interface looks different?

The Sensei Format not only has different keyboard shortcuts, but also custom addons that native Blender doesn’t have, so it would be difficult to follow along without Sensei Format installed. However, the author makes it easy to go back to native Blender if you find you need to.

Is Sensei Format , like, better than plain Blender format

I find it better in some ways, but it’s quite a bit different in other aspects. If you’re really familiar with Blender’s interface and where things are, it may be alien to you. You have to “go all in” if you install it since it really changes some things.