Guinea Pigs take months to get used to people, they are little creatures that are wired in to survive predators.
Their first instinct is to run and hide. I wouldn’t try to stroke a shy piggy
I start by sitting next to their cage and gently talking to them. This might go on for a week or two. Have some tasty veggies that you can pop in through the bars. Eventually your piggies will associate your voice with food and will start to look curious about what you’ve brought them. So this progresses to them taking food from your hand and the gentle talking goes on.
In the meantime if you want your piggies out for exercise than choose a snuggle sac or carry box, take all the hidey places out of the cage, and put the carry item in. Your pigs should run into the carry item for safety, then you can transfer them to a run without scaring them with your hands.
If you want cuddles, again pick them up by using the carry box or snuggle sac etc. and have a cuddle cup on your knee to snuggle in, this gives them security. A nervous pig won’t eat from your lap but always have their tasty treat and eventually they will relax more and start to nibble.