Here is a good article that explains the different types of vaccinations.
Critter Advocacy
The new vaccination protocol recommends that puppies should not have their first shots until they are at least 8 weeks old. If your puppy is just now 8 weeks and had shots then the people you bought the puppy from should have let you know what shots she had and what dates.
The lepto shot is to protect dogs from the leptospirosis virus but the shot itself is very controversial because some puppies have severe side effect to the shot. If your vet feels that lepto is a problem in your area then I would wait until your puppy is at least 16 weeks before allowing the shot.
How much does your puppy weigh and is she eating good? What do you feed her?