It is quite simple. Do you want to build something? Then go build it.

You notice you lack information while building? Go read it.

Not the other way around.

Unless you want to read for the sake of reading/learning, which is also fine. It improves your general knowledge. But if you want to get something done, then of course, there is no other way except doing it.

But of course, if it is something bigger, than thinking before doing it make sense. Take a pen and paper and make sketches and todo lists - and then implement them.