Welcome to the forum! Congrats on your two new birds. For starters, they will probably be quiet because they are in a new place and not sure if it’s safe. Next, they are new to each other. They are going to have to learn to be with a new friend. You will be new to them as well. They probably will need at least two to four weeks to settle in.
Colourful toys will help them to get interested in exploring.
Seed is a poor diet for any parrot. Can you find some pellets to transition them to. As well, it is really important to give them fresh veggies and fruit to round out their diet.
I am guessing they just need some time to adjust.