Here's a few items that you might find useful for websites, designs etc.
A few interesting t-shirt facts that you probably didn't know. Click the advance button to see another.
QR CODE GENERATOR
Simple. Type in your website, email, or phone number and click generate. You must click generate to refresh the app.
Then screen shot, or right click and save the image put it on anything you need or want.
Envato Place It
Similar to Canva, however more depth of designs and logos and very t-shirts specific and most designs can be purchased for a very low price of about $15 a monthly cancel anytime subscription or with a one time purchase under $40 which is really inexpensive for a custom logo design that you can edit to your hearts content.
Can also be used for product mock ups if you would be an online seller and would be in need of that.