Hmm... Well, if you want to learn, I think a good recipe to to get to know the right ratios with is pound cake. It's Flour, eggs, sugar and butter, all in the same amount. So, if you use 300 grams of flour, it's 300 grams of the other ingredients too. You pour it in whatever kind of pan you like and then bake it in a hot oven until it's golden and a toothpick stuck in it comes out dry.

Once you get that down, you kinda get a feel for how much of an ingredient you need when you bake. At least for things that you want to come out with a cakey texture.