First time cooking

It'll be my first time cooking, I just have a basic question.

If I was just making lets say....brownies. How much should I put in per serving?
I bought 2 grams for $30 the other day so I don't want to make something that's going to take like 10 grams because I don't want to spend that kind of money.
Also, how much should I eat after I make them? Percentage wise. Like 25% per person? A couple brownies?

Thanks for any help
I already read all about how to make it, but I never saw a clear cut answer of how much to put in.

well that my friend would depend on the quality (by the price you gave i'd say it's pretty good) and just how high you want to get.....i don't see how you plan on making brownies with 2 grams though....unless you are going to just like make self serve portions but i think a pretty basic rule of thumb is 1 gram of decent bud per person, but i could be wrong...i've only read alot about this stuff i've never actually done it.

has anyone ever made like a main course with marijuna like marijuana food for dinner