No, you can send off the application for the FRTOL and the PPL at the same time and get both back together.
Only advice is, enjoy it. Neither are as bad as you've built them up to be in your own mind. The RT oral is a make believe little bimble around make believe land with you doing the calls as and when you feel ready (you can even write them down beforehand if you want).
The skills test is just another pleasant bimble next to a guy who could, at any moment, chop the power and see what you do.
You wouldn't have booked them if you weren't ready, would you?