Keeping organized for taxes

Not sure what to even title this but I have a few questions for the guys who have been at this for a long time …working in multiple cities with all the different buisness licenses how do you keep track of your income per city I haven’t found a good way to do that yet…also I have found people pay mostly with cash or check and hardly ever care to get an invoice …how do you guys handle this money thing …I’m really good at spending it but management not so much !