There is no age restriction on holding PayPal/2checkout account if you have bank Ac (even if it is junior(under 18) also acceptable under PayPal tos)
No. Actually OP needs to be at least 18 years old to be able to legally create a PayPal account. Since he is under 18, he is considered a minor and can't enter into any legal contracts on his own. When getting a PayPal account, you are entering into a legal contract with PayPal.
"For an individual to open a U.S. PayPal account and use the PayPal services, you must be a resident of the United States or one of its territories and at least 18 years old, or the age of majority in your state of residence."
It's for PayPal US, but it works to the same analogy in any supported country.
The issue is not lying, everyone can do that. The real issue is that you can't really do too many things with an unverified account. PayPal will limit you sooner than later and they will ask for personal documentation, a photo id and that's when it becomes a bit riskier. Lying about your age is one thing, forging or using forged documents is an entirely new level.
@Billygoat24: It's necessary to be able to accept PayPal payments or else you'll leave money on the table. There are two ways to do that: directly with PayPal or via 2Checkout. Since you can't have any of those legally, because you're underage, the easiest would be to use a family members PayPal account until you turn 18. You sensed that right.
You need a business PayPal to connect to Shopify.
Is this a fact? I don't sell on Shopify, so i wouldn't know. I'm just asking, because Premier PayPal accounts also have the Express Checkout option, what Shopify uses, so he might not need a Business PayPal account after all.