Congrats on your new piggies!
I'll give you the advice I am currently doing with my new piggie. I've had her since Wednesday to give you an idea.
She is extremely skittish but I have put her in the busiest room in the house, that being the living room so there's constantly people coming and going. Whenever I walk past I talk to her. I take to sitting by her cage and making a LOT of noise with the veggie bags at veggie time at 4pm. She has already grown to know that the noisy veggies and me sitting by her cage means food. I will not give her the vegetables unless she comes over and takes them from my hand. This can take a long time, anywhere from a couple of minutes up until half an hour (with an old piggie, not my current, she caught on quick) but it is extremely rewarding when they take it from your hand. She comes over, takes it and quickly runs away with it. In the last few days she has taken to running less distance away and today to my shock and happiness, she was standing up at the bars waiting for the food (though when she realised it she quickly hopped down and moved back two steps

). I've had her for 4 days and she's already at this point. It really takes a lot of patience, a soft tone, constant encouragement like 'good girl/boy! in a different tone' and keeping the same routine up. She took every piece of food from my hand today and instead of backing up 4 steps as usual or running it to the bowl, she only took one step away.
She's catching on fast, which can depend on the braveness of a piggie so don't compare yours to mine. I've had one piggie who took 6 months before he felt brave enough to take food from my hand without running away. I hope this helps a lot. I talk to her constantly whenever I am nearby. She legs it when anyone else comes or goes but she doesn't do it to me. This shows you how well it can work if you work with them.
It's quite fun to watch their steps in getting braver.
