It is wise to be cautious if she hasnt had all her needles. I used to carry my pup into busy areas so she got used to all sorts of different people and sounds. I also took her to my dog club and held her so she could see the action. I didnt put her on the ground at any stage. She had the last of her 2 needles at 11 weeks old. With the new vaccines you should only need 2 about 4 weeks apart.
The important socialisation window is upto 16 weeks old. This is when you can really get pups used to all sorts of different things, but you also need to avoid any bad experiences with people and other dogs.
Puppy school will be good for both of you and you can ask lots of questions regarding her care.