My house 1st floor electric panel has been disconnected. Can I jump from active 2nd floor panel to 1st so I have electricity in my 1st floor?

Only the person that disconnected it can tell you if if can be "jumped".

Why and how was it "disconnected"

Is this a separate electric meter feeding it,

Are you wanting to "jump" merely to test or do some temp work

I had a tenant in the 1st floor that moved out, There were separate meters, the 1st floor meter was taken out by electric co. I now live in 1st and 2nd.

You will need an electrician to survey the electrical system to see what is needed to go safely and properly from two meters to one.

Simply jumping anything can overload the feeder to one apartment.