The question is a bit like, 'how long is a piece of string?'
With out knowing what you have done so far, and I wouldn't recommend saying what here, its difficult to advise specifically
I am guessing that the designers of the game have built in the need for a balanced economy, so this would be a good point to start from
What you need to do will be dependant on your style of play, and how much time you can devote to actually playing the game.
You can get quite substantial amounts from resource tiles such that you might get away with little or no production in town.
You seem to have done pretty well already by doing what you have been doing so far.
If you look at your statistics, it will tell you exactly what you have made and what you have spent it on.
Check on what you want,would like to research, learn, construct and what is likely to cost check to see is if your economy capable and adjust production and yielding if it cant.