Driving:will I fit??

Hello all, I'm UK size 26ish! Used to be size 32, I have decided upon turning 40 that I would like to drive and I have booked my first lessons for Tuesday, but I'm worried I won't fit in the driver's seat or the steering wheel will be uncomfortable and smushed into my belly. I'm starting to panic and thinking about cancelling. I don't have anyone to ask if I can try sitting in their car as I have no family or friends for that matter. Am I just overthinking??