Three times a day. However, small dogs until you set a schedule should be allowed to feed a day. They normal have very small amounts. If they do not eat, their sugar will become too low, making it sick or even die.
This is a question you should ask you vet. They will tell you over the phone. If you pup is 8 weeks old then it hasn't been weened long, right? Are you the breeder? Most breeders don't let these little one go until between 8 & 12 weeks old, depending on their weight. Ask your vet!