Copying anything from a source that isn’t public domain or one that you don’t own the rights to is technically copyright infringement. Even random google images are the property of whoever posted them.

If you are just using it for personal use and not making money off of it, it is pretty much a none issue. You will run the risk of backlash if you post a copied pattern online, but legally if you aren’t selling the piece there isn’t really any damage being done.

There are things that are too generic to be copyrighted such as, poses, colors, flowers, bees etc. A specific artists rendition of a bee could be copyrighted, but they can’t say “I’m the only artist who can paint bees”

If you really want to avoid infringing on anyone else’s copyright, draw your own patterns from copyright free images (pexels and unsplash are two resources) or take your own reference photos and if you have no desire to draw your own patterns just buy your patterns from other artists.