If you are looking for to add some scrolling effect to your background pattern you can do so with this snippet by Nils Riedemann, the pattern scrolls from top right to bottom left. This effect was achieved using pure CSS. If you need to get more background patterns, head over to All The Free Stock they have a patterns section under free stock photos.
If you are having trouble with the pen, try the archived copy on GitHub
Background Pattern Scroll Snippet
See the Pen PWyYjV by Nils Riedemann (@riedemann) on CodePen.0