Read this guide to open-source contribution.
To add the necessary contribution that will get your Pull Request accepeted refer CONTRIBUTING.md file.
Pull requests can be submitted to any opted-in repository on GitHub or GitLab
The pull request must contain commits you made yourself.
If a maintainer reports your pull request as spam, it will not be counted toward your participation in Hacktoberfest.
If a maintainer reports behavior that’s not in line with the project’s code of conduct, you will be ineligible to participate.
To get a shirt, you must make four approved pull requests (PRs) on opted-in projects between October 1-31 in any time zone.
This year, the first 50,000 participants can earn a T-shirt.
Pull requests that are automated e.g. scripted opening pull requests to remove whitespace / fix typos / optimize images.
Pull requests that are disruptive e.g. taking someone else's branch/commits and making a pull request.
Pull requests that are regarded by a project maintainer as a hindrance vs. helping.
Something that's clearly an attempt to simply +1 your pull request count for October.
Last but not least, one pull request to fix a typo is fine, but 5 pull requests to remove a stray whitespace is not.