Keith Evans already pointed this out, but your understanding of Federal debt/spending is fundamentally incorrect.
To put things simply into a single question- how can you pay your taxes if the government never spent those dollars into existence in the first place?
Spending comes first, then taxes. The national debt is just the dollars the government has created and not taxed back yet. ‘Paying down’ the debt is meaningless (or even dangerous). Simple concept, but it confuses the hell out of people.