Since you've just purchased PI8 and the pictures are going to be displayed on the web, you could try making a rectangular 2D path object, convert it to an image object and use the image fill tool to fill a texture to it. The fill tile is is scalable, and you could use the preset tiles or import your own. You can also add a canvas texture to your images if you want. You'll find that PI8 has a lot more features than PI5.
Familiarize yourself with the tools you have, instead of buying everything on the market. I find that PI is adequate for web images and home printing.