Congrats on getting your rats.
Yes just give sometime.
One thing I suggest is to not feed treats through the bars of the cage. That can teach your ratties to bite anything that comes through a bar.
A good way to entice a nervous rat out of a cage is by putting the cage on the table. Add some hidey boxes, towels etc on the table. Then open the cage. Put some thawed peas in a bowl--or other treat--Rats just love green peas thawed out. Then let your new friend come on out. When he is out, just let him explore the table. Put your arm on the table and let him get used to you. If he climbs up, great. Once you get your little one to trust you a bit, let him do some shirt diving. Rats love to dive down your shirt. The best way to do that is by wearing two shirts. That will save your back and chest from being scratched up. I, of course, don't follow my own advice 90% of the time and am scratched up everywhere
Rats shirt dive to hide and feel safe. Plus it helps them get to know you. I also socialize my rats by putting them in a safe room or area---bed, bathroom, hallway---and just sit there with them and let them run all around and on you.
I've had 9 rats---two came to us socialized. Two came from Petsmart and were bitey and still are after a year. I think they are the exception rather than the rule. We got 5 6wk old boys--they are now 13wks. They weren't very social at first. We had them in an aquarium tank at first until their cage arrived from e'bay. It's big 30X18X55. So for us, in a tank, they were easy to catch and train. After 4-5 days, they were clamoring to come out and play. Now most of the time they come the door of the cage begging to come out. Well except for my Jinx. While he is fine to be out and stuff. He isn't as friendly as his brothers. You will find that, like people, rats have different personalities. Some are go, go, go. Some are more shy, while others would just love to sit on your shoulder. Girls tend to be more curious and definitely more active. Males are lap hounds--that's their reputation anways, my boys are young so they still are very active.
Glad you joined the group. If you have any questions, which I'm sure you will as things come up
, feel free to ask.