I don't quite understand what you mean by software. Something like an excel to keep all expenses and income? Here you need something more manageable, especially if you are new to this business, and in Excel, it isn't elementary to create such tables. When I opened my business, I wrote everything down on paper, which I advise you to do, because this way you will understand precisely how much money you have going out and how much is coming in. In general, as a novice entrepreneur, I can advise you to start expanding now with services of the type
innovation-park.eu and secondly, read as much literature as possible on the topic of doing business. Good luck to you