Finding an OSS project to contribute to (H.S. Edition)

Hello. I am a junior in High School and I'm looking for advice on how to get into open source contribution. I am skilled in the following languages (ordered from high to low proficiency): Java, Python, Perl, HTML/CSS (I know this isn't a REAL langauge), C. I've tried joining some projects in the past, but they have either fallen apart, already had too many active contributors, or had a codebase that was too deep and complex for me to understand. I'd be grateful for any suggestions the HN community could offer me.