That depends on you and what you buy. Most teenagers like hanging out with friends at the mall. Real mall shopping has pitfalls, too. You might:
Need a ride to get to the mall;
End up parking what seems like a mile away;
Encounter crowds, lengthy checkout lines, and rude sales people.
Some downsides to online shopping are that you:
See pictures rather than real items;
Have to wait for delivery;
Have to pay shipping costs to get and return any items.
However, you can do both. Wherever you shop, be smart and savy to get the most for your money.