We are in the same boat, you and I. I'm also an aspiring writer, and I am a senior in law school.
In regards to scheduling, I think the best approach is to write a little bit everyday. If you write a page a day, you'll have 365 pages in a year (totally not stolen from Stephen King's On Writing). You can try to fullfil a quota of words or pages per day, or you can write as many words as you can in a given time. See what fits best for you. Personally, I think that you should sit down for, say, an hour or two every day like I do, or have a small amount of words as a goal. If you try to go with more than 2,000 a day, you'll spend a lot of time and get frustraded. If you cut unnecessary things like social media any stuff you'll be able to have the time.
Although I did try, I never became succesful in wattpad. I published some chapters of an abandoned novel, some short-stories, and quit when I didn't see it paying off. If you want to go through that path, publish one chapter a week, and market it actively. You could also engage in contests. However, I'd strongly recommend Amazon KDP instead. Wattpad is infamous for the low-quality content and, unless you manage to get tens of thousands of followers there, you'll earn no money nor opportunities to publish traditionally. It'll be a waste of your time.