While I don't know of any particular open source projects that would be good to jump on in particular, I do know of a few different resources that can help out in that area. Firstly, I would recommend the Tensorflow developer's youtube channel (and obviously the TF site and documentation). They post series and videos of learning TF 2.0 and other how-to/advanced uses of it, as far as general ways to enhance your knowledge and learn about things, it's a good starting point. I'd also recommend the book, Hands-On Machine Learning with Sci-kit Learn, Keras, and Tensorflow as well (2nd edition has been updated to tf2.0 w/ lots of good examples and starting points (aimed at a more beginner level but even advanced users could probably pull a few tricks out here and there). Hopefully these are some adequate starting points into the world of Tensorflow.
Best of luck on your journey,