Please help me!!!?

I possibly might adopt this puppy. It was from a rescuer who took in a pregnant dog. The puppy is 6 weeks old and doesn't have any shots. This person is not a breeder. He simply helped a poor dog off the streets. I was wondering exactly at what age it will need its shot.[btw its a female] How much will the shots cost? I wanted to know this beforehand and Iv'e been researching but can't find the information I exactly need. How much do you think the spaying would cost? Thank you to all who answers because I really need to know. Thank you again