Can I charge my MacBook Pro 2015 without using MagSafe 2 power port?
It is neither possible nor advisable to charge your MacBook Pro using Thunderbolt or USB ports.

It is possible that either your MagSafe 2 port or the charging adapter is damaged. Please stop plugging in the charger if you spot burnt marks on either one of them. It’s recommended that you get your MacBook Pro inspected by an authorized Apple technician. You may be eligible for free service and replacement if you are covered under AppleCare.