Do you<p>- look at the tests?<p>- pick a function and follow it in a debugger?<p>- pick a task and figure out how to implement it?<p>- pair program?<p>- etc<p>Personally, I've found picking a task and start doing it is helpful
I wrote a whole blog post about that:<p><a href="https://letterstoanewdeveloper.com/2018/09/24/learning-to-read-code-is-more-important-than-learning-to-write-it/" rel="nofollow">https://letterstoanewdeveloper.com/2018/09/24/learning-to-re...</a><p>Tldr:<p>* Do a high level scan<p>* Dive deep on one part<p>* Use the scientific method. Create small experiments to help you build your intuition about the system.