How to bond with shy guinea pigs and make them more comfortable?

Hello, and congratulations on your new guinea pigs! Guinea pigs can become very social with humans but it can take some time if they have not had much interactions with humans before. Try to very gradually get them used to you by offering them something tasty such as fresh vegetables, fruits, and commercial treats from your hand. Eventually, they will start to associate your presence with treats, and will be more willing to come out to play. While they are eating a treat from your hand, you can try to gently pet them on the top of their head. Talk to your guinea pigs regularly so they get used to your voice, and ideally put their cage in a room where you are often in, so they get used to your presence as well. They can also learn their names if you use them often enough! Don't try to pick up/hold your guinea pigs until they have some comfort with taking a treat from your hand and putting their front paws on your hand. When you do try to pick them up, hold them snug but not too tight, and always support their bum to avoid falling.

I hope this helps! Enjoy your little guys. They are great pets!