I can only say that my lad was all set to go to university, and then decided not to go through with it, because, he said, "I don't know what I'd be going for".
There are jobs out there with training for A level applicants, and your prospects won't be lessened if you don't go to uni. OK, if you do go, you might be able to fast-track to management, but you'll probably be in the same position by the time you're thirty, whichever route you choose. Neither would it hurt to take a year out to either work or travel (or both) and give yourself a little time in the real world before you decide what to do. You even have the best of both and do an Open University degree.
The most important thing is to do what you want to do, not what other people (no matter how well-meaning) think you ought to do.