FREE people search sites?

Iv been looking for my Brother , dad and grandmother for a few years now . Im 14 years old . I searched every where for them , but each site you have to pay to see there adress and number . Are there any COMPLETELY FREE People finders ? As is you get all info on them for free with no charge what so ever ? If i could find there adress or number , it would be amazing .... Can anyone please help me and my mom ?