I've started learning but haven't done my theory yet, it's in a couple of weeks now. I would say if you're confident and want to get driving as soon as possible, then just do your theory test as soon as you can. I'm learning to drive pretty slowly since I'm nervous so that's why I decided not to book my theory test until I was a few lessons in and certain that I was going to keep at it.
I started driving 2 years ago and then stopped after 6 lessons, so I'm really glad I didn't do my theory test then, because I wouldn't have passed my practical within those 2 years. I started learning again last month and I'm certain that I won't be stopping or giving up any time soon, and that I should be doing a test within a year at least, so that's why I'm doing my theory next month now and why I didn't do it before starting lessons.