Can I pick up a couple of the turtles and hold them?
Why did you want to pick up a couple of turtles and hold them?
I wanted to feel their heartbeats and be aware of the fact that they're alive and their hearts are beating.
I understand your curiosity, but picking up wild turtles for your own sake isn't the right thing to do. You could injure them, or they could potentially injure you. It's best to leave them alone unless they're in danger.
It's good to learn, but do you think it's too much for me to hold and feel the heartbeat of a couple of turtles?
If you want to learn more about turtles, it might be a good idea to go to an aquarium, not interfere with wild ones. I'm sure the people at the aquarium will be happy to help you learn more about turtles and lots of other animals.