No. There is currently an internet rumor going around, but its fake.
The Stafford Act was enacted by Trump last week to release aid and testing to the individual states more quickly.
The internet rumor is that Trump is about to enact the Stafford act, in which we would be quarantined for two weeks—so stock up on groceries. The rumor is bogus.
The Stafford Act was for the release of aid where it was being held up. It has nothing to do with quarantine.