Legal Question in Credit and Debt Law in Georgia

If it is a "side agreement" that contradicts a judge's order, no.

If it is something else, there's no requirement that contracts have witnesses or notaries, so it might be, depending on the content.

What are you trying to accomplish? If this note is some kind of attempt to change a judicial order, then you need to go back to court in order for the agreement to be legal. If both sides agree, it will not be expensive for you to get a lawyer.

Assuming that this is some other kind of agreement that does not seek to alter any court orders, is this just a straight promissory note? You can get promissory notes online for free at www.ilrg.com.

It does not have to be notarized, but having the signatures witnessed by a notary eliminates problems of proof. You don't need any witnesses. The note/agreement does have to be signed by the party promising to pay money.