They just need time to adjust to all the big changes. Kittens are curious, but all cats can be apprehensive with big changes.
You are lucky they didn’t hide straight away, as a lot of kittens do. Our kitten was also quite confident, he walked straight out of the carrier, explored, ate, used the litter tray etc, but when he got tired in the evening, he took himself under the stairs to sleep, as it was enclosed, it made him feel safe and secure.
it probably took him around a week to start sleeping on our bed with us and around two weeks to get on our laps in the evening and chill with us. Some kittens take quite a lot longer.
just give them the space when they want it and never try to force interaction. I’ve always tried to let my cat come to me, rather than me smothering him and I’ve always tried to read his body cues to know when he doesn’t want stroking.
good luck, they don’t stay little for long. I miss ours being little.