Hi everyone!
Below is a set of links related to the ongoing Hacktoberfest event, including a few sites to help you more easily find projects to work on.
To help find projects to work on, these sites let you filter by language, issue labels, etc.:
This isn't specific to Hacktoberfest or making pull requests, but
https://github.com/ziadoz/awesome-php is a great list of all things PHP - libraries, tools, and tons of other resources.
Hope these help!
Chris