Gas Price is how much ETH you are willing to pay for a unit of Gas. So the higher the Gas Price, the more ETH will be paid for each step in the transaction.
The higher the Gas Price, the faster your transaction will be accepted by miners. However, people usually don't want to pay more than they have to.
So what should I set the Gas Price to in order to make sure the transaction is confirmed on the regional chain in a normal time (eg 10 mins)?
You can check the following link: https://ethgasstation.info