Oh wow, that’s a bit of a big question. I’m really not picky when it comes to style or structure or content, and obviously I’m just one person, my opinion is just an opinion. And I’m sure you’ve heard all the general writing advice before, so that’s all good. In Star Wars specifically, I think it definitely does help to have at least some experience with the worldbuilding details of the series. It’s a very daunting universe to get into, but the little quirks of speech and terminology are always nice to see. I really don’t think you need to put any more effort into adhering to canon than you want to, though, which is maybe a bit ironic. It’s all about having fun. What I like to do, because I read the supplemental material, is I collect words and phrases I come across so I can use them later. If you’re at all interested in the extended universe, I’d say that’s a nice place to start. Don’t get hung up on it, though. Even if I know I would have used a different word or described something differently, as a reader I don’t get thrown off at all when I see stuff that doesn’t perfectly fit with canon.
Really the one thing I would emphasize is that it’s great to get a good feel for your characters. If I can hear their voice in the dialogue, and I can imagine them acting in the way that they do, I am very very happy. That’s really just writing in general, I guess, but it does so much more for the flow of a story than making every detail match the canon.
Uhhh yeah, I think that’s all I’ve got. I’m really a “do what you want, don’t hurt people, and have fun” kind of fan, but those are just my thoughts. Maybe other people would like to add the kinds of things they like to see as a reader too?
Hope that helps! And good luck with your writing!
~ Jacen