Id try and focus on 1 at a time if i were you since alot of the principles of limit and no limit are in direct conflict. e.g. in limit you generally dont fold fairly decent hands in all but the smallest pots whereas in NL you are usually looking for reasons to fold.

The other problem with limit is that online limit is pretty much dead these days. I hear its still fairly beatable live but you might not get very far trying to learn it online.