This is my first time doing taxes as a courier/driver. What is "interest expenses for vehicle"

Hello,

Interest expenses for vehicle include includes interest you paid on money you borrowed to buy a motor vehicle.  

You can find more information here:

https://www.canada.ca/en/revenue-agency/services/tax/individuals/topics/about-your-tax-return/tax-return/completing-a-tax-return/deductions-credits-expenses/line-22900-other-employment-expenses/motor-vehicle-expenses/interest-expense.html

Hope this helps!