There have been websites (and maybe there still are) that allow finding projects with the "beginner friendly", "first contribution", "good first issue" tags. However, I do believe that there are better ways to funnel motivated but undirected developers to projects and that can be by using external metadata like ratings (perceived code quality, pull request experience, response time for PRs, etc.), tags, links to ideas ("idea implemented partially|completely} in project XYZ"), and more.
Especially connecting it to people's ideas, wishes, and even bounties might garner support.