If someone asks you "do you have any questions?" after teaching you something, and you don't have any direct questions, use that opportunity to ask them to check your understanding of the information they just gave you.
Instead of telling your trainer that you have no questions, ask them to listen as you repeat your understanding of their instructions. This way, they will have the opportunity to correct any missteps or misunderstandings on your end, and you will have the opportunity to check your understanding and clear up anything you might be vague about. This is much preferable to messing up later due to a miscommunication you never cleared up.
Example: "To make a pizza, you need to weigh the dough, stretch the dough, spread a couple scoops of sauce, then add toppings and cheese, any questions?"
"Actually yes, can you just check this really quick: so I weigh the dough, stretch the dough, spread two scoops of sauce, then add toppings, then add cheese?"
"Oh, no, I usually add closer to 2.5 or 3 scoops of sauce and I put cheese down before the toppings."