> In my (probably unpopular) opinion, it's better to start contributing to open source projects after having some experience with real projects at work, not the other way round.

Or don't start by contributing code. There's a lot of work to do in areas like bug triage, reproducing issues or creating setups which do that.

I used to be part of a commercial, but open-source project. Unfortunately we didn't have the resources to scrutinise every pull request that arrived and I think few projects do.