I just went for medical, they start with a urine test and then do a hearing and vision test (with and without glasses/contacts).
You've also got a blood pressure check and then they will also ask you to bring any vaccination records.
They will suggest that if you're unsure you can go to your GP prior to your medical and get a serology test to see what you have immunity for and what you still need vaccinations for.
I already had Hep B and MMR as a child but got them again because my immunity had lessened.
They will be looking for:
Hep A
Hel B
MMR (measles, mumps, rubella)
Chickenpox
ADT
Like said above they'll get you to bend, stretch and check your key joint movements for any issues.
All up my medical cost me $300, I went to my GP straight after for my vaccinations and for Hep A, Hep B and MMR which cost me $140.
Hope this helps!