The shelf-life is indeed 24/36 months both of Test and Deca when you store them properly.
but it's obvious we don't know whether your Test and Deca are still good enough unless we know the expiry or manufacturing date. Even then, you should make sure that they were stored properly.
In whatever the case, Test and Deca are not expensive steroids. You could get new ones if you are afraid that they might have gone bad.
also, sorry if I'm wrong but you seem like a beginner so I wouldn't do Deca. for a beginner, testosterone alone is enough.