Some businesses are highly complex whereas other businesses have a simple business model and very few employees. If you see your doctor for a personal health check they will start off with some standard tests and progress to more detailed tests if required. It is the same with businesses, there are significant similarities between most businesses so much so that standard health checks can be performed on almost any business. It is possible to run a business health check based on benchmarks from similar businesses. This however does not tell the business owner or manager if the business is going in the direction that they would like to pursue.
The regular payments you have so far found will form the core of your household budget. You can now turn those into a formal list, either on paper or on a spreadsheet, and put the amounts into the next column, with a heading notifying the month. Before moving on to the next phase, add a further 11 columns on the paper or spreadsheet, with the headings changed to appropriate months until you have a column for each calendar month for a year. I have prepared an example budget spreadsheet to help you.