There is a toilet in the house that doesn't flush fully. It takes like 3 flushes to get the paper down. Plus there is a pipe outside that has dried up toilet paper that looks like came from out of that pipe. The pipe is not covered comes up from the ground and is PVC.

You have a blockage in your main sewer line. Snake from the pipe coming up from the ground. After clearing the drain line, put a cap on the pipe.

Harold is correct. What you have is a blockage downstream from the open pipe which is a cleanout without a cover. Snake from there and purchase a PVC cleanout cover. Good luck, Tom