I'd actually advise that you start out with several shorter stories. If you look at the profiles of the authors that write those epics you will see a number of shorter stories along with the occasional Epic. If you delve deeper into the writing workshop you'll see a number of authors that showed up to the site, talked about writing an epic, then got burned out and never showed up again.
I'd suggest that you start writing the slice of life stories you've come up with in small portions where you only have one POV. Switching POV isn't popular here and is difficult to do well in a CYOA. This will leave you room to improve your writing with editors and also lets you use future or previous characters as Easter Eggs.