I think it's really, really hard to dig into somebody's else undocumented & dirty code. And, I think, to start I need to add some feature, learning by the way

I think it's really, really hard to dig into somebody's else undocumented & dirty code. And, I think, to start I need to add some feature, learning by the way of implementing it, about how project is organized, and thinking about how can I refactor its code, etc.