A winning spreadsheet could make you a fortune. If you could effectively identify what many people want and are willing to pay for, and can make your spreadsheet easily accessible, you could be cashing checks for the rest of your life.
Judging by this fact, the recommended course of action is to hire the services of a specialized company, a firm that will take care of all the details and subtleties of the spreadsheet programming in your place, and provide you with a ready-made or tailor-made spreadsheet solution that outperforms your expectations.
Most spreadsheet applications have built in formulas and functions that will do the math for you so you don't have to. You can keep a running balance of your accounts and you can have each category totaled as well. You can keep it as simple or make it as sophisticated as you please.
When VisiCalc hit the scene back in the eighties (in the last century), the relatively small group of Apple II users went crazy. It was like manna from heaven for the poor accountants, scientists and engineers who were used to filling in enormous analysis sheets with a pencil. Now, they could use VisiCalc to do the same task, AND calculate the result automatically.