lookups for current. vs. prior month, current year vs. prior year ytd

Hello. I have financial information for each month for two years. I would like to create formulas that would change based on cell value for current month vs. prior year same month, current year vs. prior year YTD. Things like that. I would like them to update based on cell values (January for example) I've attached a spreadsheet with sample data and the classifications that I need. Multiple ways of getting to the same result would be welcomed. Thanks

Helloooooooooooo

This seems like a lot a people would know this one because it's sort of the basics for accounting/finance. Please help!!