Writing is something I think I'm better at then drawing, though Trent only came about because of a trip our family took to an extremely tiny cabin. I've reworked and revised so much over the years and it's still currently at 34 pages, and though it technically ended, I still edit it from time to time. It's essentially just haunted house but a bit different. I don't wanna say too much because I do have hopes to one day publish it.
Anyway, it can be hard to figure out what to write about, and even difficult to tell what your skill is at. You can start out small and simple, or derive ideas from personal experiences or whatever you like and enjoy. Or for things you disgustingly hate. Sorry for sounding generic but that's all I can think of.
To tell if you're decent is tricky because people, as I've learned, have different tastes in author styles. An example being that my own boyfriend dislikes my usual style because I tend to be a bit wordy and longwinded for his tastes. You don't actively have to try to develop a style if you don't want to of course. Keeping decent grammar and interesting word choice should be enough to keep you decent.
Having characters that are all over the place isn't bad either! You can always separate them into their own stories, or have stories become part of a larger world or even a whole universe! If you really cannot use them right now, don't burn them. Save them for later and possibly reworking.
Apologies for the long post, hope this helps a bit