Just don't get your socialisation advice from your vet
Most attempt to offer advice if you ask, but really, if you want the right advice make sure you ask on here or call a local trainer or dog club
Socialisation doesn't just mean meeting different animals and people. It means introducing them to sights, sounds, different surfaces, etc that they will experience throughout their life. This helps ensure confidence around those people/animals/objects/noises during their life, instead if fearing them.
Good Luck with the training and keep us updated