You need to decide what you might be interested in first. Then search for a small project on Github, Bitbucket5, etc., that does something like that or related to that and see if they have any open bugs that need fixing or a list of features that they want implemented.
It's probably best to ignore any projects that have not had any recent contributions at this stage because the maintainer might have lost interest so you won't get any feedback about your contributions.
It's probably best to ignore any projects that have not had any recent contributions at this stage because the maintainer might have lost interest so you won't get any feedback about your contributions.