For eye testing, you'll need to make an appointment with one of the KC/BVA opthalmologists, not your usual vet. On the BVA website mentioned above, you can find a PDF file with a list of all the eye testing vets as well as the info on prices etc. Eye testing is done annually from 12 months old.
Hip scoring can be done from 12 months old - your vet should be able to do the x-rays (more info on the scheme is also on the BVA site).
Your vet can also take the blood samples/cheek swabs for the DNA tests but not all vets have experience of these tests so you may have to direct yours to the relevant websites (Optigen or Antagene) so they can read up about it all first. DNA tests can be done at any time.