Are you looking to buy Diary of a Wimpy Kid merchandise?
I definitely have a favorite places for finding Diary of a Wimpy Kid Shirts: Redbubble.
Here are a sample of some of the shirts from Redbubble:
Amazon also has some Diary of a Wimpy Kid shirts now sold by various distributors. They have a lot of Loded Diper shirts but also a couple with the general logo plus some sayings like “Sike Don’t Do It.”
Are you looking for something more original? Etsy has a small collection of shirts (mainly Loded Diaper) starting at around $9.