Rental Payment Track sheet

We're looking to have a sheets spreadsheet created to track monthly rent payments. we have approximately 50 units, and the rental portion the tenant pays each month may change as the majority of them receive assistance through section 8. this also changes the portion section 8 changes. the overall total rent amount doesn't change monthly but it may increase annually. for example they may be responsible to pay $190.00 for January but in March they may be responsible for only $150, so id like it to auto fill their portion to all months unless specifically changed, and once changed only update the future months. also would like it to auto populate late fee charges which are $10/day starting on the 5th day of the month.