looking for advice/reassurance

hi guys! i’ve owned puppies before but have always had the help of another dog with helping the puppy navigate being a dog, gaining confidence, and a play mate! We got a new 9-week-old puppy about three days ago — he’s so cute and so little, I love him to bits! But he’s very timid and scared, and he tends to cower if we walk toward him. He’s also not very food-motivated; in fact, he barely touches his food, which is making me anxious. This is my first time ever picking a puppy from a breeder, and the guilt I feel watching him become a shell of himself without his siblings is breaking my heart. My dad and I got the pup because we’ve been looking for a companion to add to the family. Our puppy is very clingy with me — he follows me everywhere and always wants to sit, lay, cuddle, and play with me. But when it comes to my dad, he’s quite standoffish, gets scared to approach him, and doesn’t really interact with him. I really want him to bond with both of us.

Maybe I’m just stressing myself out with all the research I’ve been doing. I know it’s only been three days, but ah, I’m just a bit worried. Sorry for the long-winded post, but any advice would be very appreciated!