Guinea pigs are very social creatures. They love it when you give them attention. However, they will often be very timid on their homecoming. They have spent many days in a pet store, a place that's familiar to them. That is their home. That is where they are comfortable. But when you bring them home they will have many different surroundings that will make them timid and scared. So you have to be very gentle with them in how you handle them and how you approach them.
It is best that you don't try to pick them up within the first few days. To them you are still a stranger, but don't worry, there are ways to win them over. One tip to take into consideration is that when you approach their cage, don't hover completely over it. Always try to be at eye level with them. When you hover over them they see you as a predator and that will make it harder to win their friendship.
The best way to get them to trust you is to feed them snacks.
This is not as easy as it sounds because you shouldn't just throw snacks into their cage. You should place the snack right outside of their cage door ( the cage door should be open) and you stand right behind the snack a few feet away. Let the guinea pig come to the snack. If it doesn't then close the door and don't give it the snack and just walk away. By walking away you are actually letting it know that you don't intend to hurt it. If by chance the guinea pig does go for the snack, then do it again on a daily basis. Do this until the guinea pig lets you pet it.
Bringing Your Guinea Pig Home