Hi I'm new. I done a work out yesterday and today my legs are really hurting me! And can I change days of challenge exercise? As I want to work out mon-fri and rest sat-sun
Maybe the challenge is above your level right now. Of course you can change anything you like, you are in control if your own progress.
Personally, I wouldn't do much more leg exercise while I was still sore from the last workout. Stretching, yes. But I believe in giving my body a chance to heal from one workout to the next.