You need to buy a "real DAW" so you can work with Melodyne in the track of the song. Nothing beats being able to hear the song playing and listen to the fixes you're making.
One big reason is that you can't always simply just pull everything back to perfect pitch and expect good results. Sometimes the part actually sounds better when it's a bit sharp or flat...and if the part was in need of some correction to start with and you're working in the stand alone and can't hear the backing tracks for a reference, it will drive you crazy trying to dial in your fix.
More than one time, I have done a fix from where it started off pitch to pulling it to the perfect point and I had to back it off halfway between those points..... without the backing tracks you're shooting in the dark.
Get a good DAW that supports the timing data Melodyne needs.
Sonar's Music Creator 7 Still $20 for the download.
https://shop.cakewalk.com/1244/catalog/category.60467/language.en/currency.USD/?id=ZUxliJQ5m4