It's October, and for the third year running, Digital Ocean is running Hacktoberfest in partnership with GitHub.
It works like this: you sign up, submit pull requests to open source projects during the month of October, and if at least four of them are merged, you qualify for a limited edition Hacktoberfest t-shirt. It's a nice shirt, too.
On Exercism we've received 336 pull requests so far this month. A whole 262 of those have been merged.
If you want to find some low-hanging fruit to get started, go ahead and do a search on GitHub with the following:
Another good search term is label:"good first patch". That might bring up the same issues for now, but we use it the rest of the year as well for issues that are fairly straight-forward to tackle—even if you're new to contributing to Exercism or to open source in general.