My recommendation tho of course is to find an existing project you’re passionate about, find their tracker, and dig in! Few softwares are ever truly done. Make one you love even better.
The random driveby contributor strategy has never worked for me. Most of my projects had me as their "long term" contributor or the opposite, I let one of my contributors become one.
Organization is critical to the success of a project and you're basically telling someone to forget about it and waste the maintainers time.
Also, there's a lot to learn from closed PRs.
Best way to avoid having your pull request rejected, is to make sure the change is actually wanted, which you can figure out by communicating.
So if some random webapp has a button in the wrong place, don't open a PR moving the button to the right place, open a issue and confirm it's wrong, and confirm the maintainer(s) would be fine with the suggested change. If something is unclear, clear it up before spending time on the PR.
Once consensus is reached, it'll be trivial to get the PR merged.
- https://github.com/issues?q=is%3Aopen+is%3Aissue+label%3A%22good+first+issue%22+language%3Apython+sort%3Aupdated-desc
- https://github.com/issues?page=2&q=is%3Aopen+is%3Aissue+label%3Ahelp-wanted+language%3Apython