8 week old puppy has ticks and fleas what should i do?

I just bought a puppy from a breeder and it had ticks and fleas. i have use a tweezer to get the ticks and i do not believe i got all of them because that would just be too good to be true. However, it still has alot of flees. the pup is 8 weeks old. Whay should i do? Also, he isnt eating and hes sleeping alot. i juat bought him today. Please help me!