Multiple States, Where do I file

Hi,

Due to Covid I worked remotely.  My employer is in Maryland and my W2 has Maryland taxes withheld for the year.  I lived in Maryland 1/1/20 - 3/20/20, I think I need to file a Maryland Part year resident to get a refund for my tax withholding.  The issue is I moved to Michigan, my parents home, from 3/21/20 - 10/31/20, Do I file a Michigan Part year resident tax return for the income I earned from my Maryland job during that time period?  Michigan wants to charge me a penalty for not paying estimated taxes, do I need to pay it?  I then moved to Florida from 11/01/20-12/31/20.  No Florida income taxes, easy or do I owe Michigan for those two months because I lived in Michigan for more than 6 months during the year.  Also which state do I pay taxes to on Dividend and Interest income? Thanks.