I have just adopted two brother guinea pigs from a rescue and they are terrified, what can i do?

for the first 2-3 days, dont handle them. let them get acquainted with their surroundings. then slowly you can rest your hand near the cage, and eventually them will prob come and sniff it out of curiosity. dont keep them completely secluded from the rest of the family because then they will realize that your family will walk around the cage and in and out of the room and that you mean no harm to them.