What Software Program Is Easy To Use For Designing Teespring T-shirts For Facebook!

Are there any software programs or online websites to help design
t-shirts for teespring for a newbie that doesn't know Photoshop.

I'm thinking of buying some software or subscribe to a online website
like Covert T-Shirt Builder or T-shirt Ad Builder

Hi, i'm a graphic designer and digital artist,so i can create good designs but i need a good seo expert for collaboration,if you can offer such,then lets discuss