My pit bull had some pups and they are 2 weeks old and have fleas on them what can I use to get the fleas off them

Go to the vet and get a flea and worm treatment specific for nursing moms. Don't treat the pups, unless your VET prescribes something for their specific age range.

There really isn't anything on the market safe for puppies this young.

I would do as Aurora suggested and get them to the vet so they can prescribe something for mom.

For the pups you can bathe them in a tub of luke warm water (not too cold, not to hot) with a little dish soap in it. The dish soap drowns the fleas (regular water won't)
You will need to thoroughly dry the pups unless you have a heatlamp installed over the whelping box, otherwise they can die from the cold.

Wash all bedding and vacuum all carpets. You will need to do this every week until they are old enough for a proper flea treatment. The bathing kills the fleas, but not the eggs, so they will just keep re-hatching until you use a product that kills the eggs as well.

It's a very serious issue, pups this young can die from a heavy infestation of fleas as they cause anemia. At 2 weeks they are also due for their first worming treatment.

Dawn dish soap is the best and gentlest to use. But I would avoid bathing 2 week old pups, until mom can get treated. A lot of times the Vet can prescribe something safe for both mom and pups.

Yep, it's always safer if you can avoid a bath. For animals that were originally wild, they sure do take a lot of care.

You should try using dawn dishwashing soap! It really works! Bathe the dogs in it and then pick any remaining fleas off!