Mr_greyhame has got it to a T!
After that the first week or so will probs be working through a loaf of induction stuff on the intranet, it doesn't take long at all and your TL most likely won't have extra work for you (it can be a struggle to keep new starts occupied until training).
I'd really recommend using all the extra time you'll have to read through development opportunities etc on the intranet, see if there's mentors in your area of work, get a good understanding of what interests you if anything.
That way when the work ramps up you've already done the research and it looks great to your new manager if you are proactive in your development!
If you aren't interested in that (it's okay if you are happy staying at your current grade) then the intranet is full of information to just browse whatever you are interested in!
Best of luck, in my experience everyone is very nice and supportive! It can feel overwhelming sometimes but we all felt that way at the start and no one knows anything! Just have a good attitude and ask questions and you will do great ☺️☺️