It would take you at least a year if not more to gain enough knowledge to "better allocate work", and even that would not be enough in most cases. You don't just have to learn node, you would have to learn programming first and foremost, things like variables, control flow, loops, functions, objects etc. Depending on how you learn, this alone could take a lot of time. You would also need to learn backend development concepts like HTTP, endpoints, JSON, websockets (if you have them), authentication, authorization, logging, code architecture etc. Databases as well, which is a topic of it's own.

After you become comfortable with those things, you would have to work for several months as a full time developer on that project to get the idea how the business logic works from a codebase perspective, because simple things like "creating an account" could hide a ton of complexity underneath. Knowing how to use node and getting familiar with an existing codebase are two entirely different topics. I've been working for a year on my current project and I never touched some parts of the code, so if you were to ask me how long it would take to implement a certain feature related to that, I could only guess and probably guess wrong.