The bill is most definitely a fake and whether the claim that it is gold can be heavily contested. In the US, there is no bill denomination that is $5000 as well as any with the former president's face on it.

According to the U.S. Treasury Department, there are an estimated $70 million worth of counterfeit notes in circulation, with approximately 1 counterfeit note in circulation for every 10,000 notes of real currency, up to a limit of $200 million, or real banknotes. One counterfeit note for every 4,000 notes. However, these figures are based on annual counterfeit seizure rates, and the actual counterfeit inventory is unknown, as some transactions have seen counterfeit notes successfully circulated. ...