Hey!!! Congrats on the loss! That is AWESOME!
I'm glad the hunger pangs have died down.. after a few days your body slips into Ketosis, which suppresses your appetite and turns your body from a carb eating machine into a fat eating machine. Basically instead of looking for carbs to get energy, it uses your fat stores... which in turn helps you lose weight faster
Way to go on an AWESOME 1st week!!! And as for the tiny slip up... we're all human. Part of this process is learning to forgive yourself and learn from mistakes rather than beat ourselves up over them.
As for the exercise, I'm not sure how your program works, but for mine they told us to not do ANY strenous exercise until the fasting part (the shakes) are over, if i remember correctly, it's because anything that will cause muscle mass to grow, can damage your body while in ketosis and dropping weight rapidly. Walking and yoga is OK, and anything your body was already used to (Minus weight training).. but like if you have been doing kick boxing every week for 20 years... you can still do that. But don't add too much otherwise you might do more harm than good.
Good luck on Week 2