There really isn't no "quick" way to make money unless you are fond of spending real money for nobility and trading it in for gold. This game was developed to be time consuming. It takes awhile to grow, it doesn't happen overnight. There are ways to make gold a bit faster, such as utilizing max plunder (see forum post on max plunder, id link it but am on phone right now). Defense buildings and guilds provide the most plunder so building a good amount of those will increase your max plunder. Id recommend having only guilds and defense buildings until you unlock 25 land and t4 buildings and begin to convert to your desired build. If you're already at that point, sadly I can't offer further suggestions.