@Mirka1
(a) A US person ( citizen/ GreenCard / Resident for Tax purposes ) come under the rules of FBAR and FATCA. Even if you do not have any income in USA ( requiring a return filing ) FBAR is required once you cross the threshold of US$10,000 aggregate if you own and/or have signature authority over foreign bank account(s).
The FATCA ( form 8938 with your return ) has a higher threshold but include other assets ( liquid or near liquid ).
(b) The sale / alienation of real property / assets need to be reported to the IRS / State on your return for the year when the transaction was consummated.
(c) Gifts from NRA ( assuming that the donors were Non-Resident Aliens ) may also need to be reported depending on whether the amount was equal/greater than US$100,000. If the donors were US persons, then they also needed to file form 709.
All this leaves me at a loss to understand exactly why you never had to file a return ? When did you enter the USA ? Was this your first entry ? When did you get your GreenCard ? Which country are you from ( for purposes of Treaty articles and double taxation / foreign tax credit etc. ) ?
I will circle back once I hear from you
pk
