The attached video will guide you what you can do to make you free from any copyright issues.
Collect some basic knowledge about copyright laws that will help you a lot with your designs.
Arrange all the required authorizations in case you are using any other designs, brand names, logos, etc.
To get it printed on your products.
It will be perfect if you create your own original artwork for POD to use freely.
You can visit Printchester to upload your original artwork on quality products to sell them by going to the link - https://printchester.com/