For most people the ability to sing and play comes faster than they expect. It will just take some time not a lot. As a beginner your brain is already on over load trying to do many new things at one time.

As you practice scales or any thing, talk or sing while doing it. You may be surprised how much can happen in just 5 days if you do it while you practice.

Not saying you will be good at it in 5 days, just that you will advance faster than you seem to be thinking now.