You will love this trip! Altitude is a problem for some - try to be in excellent physical shape to get the most out of this trip. And don't be shy - try everything and add to what
ABD offers. The museums in Cusco are open until very late - go visit OYO. The horseback riding at Sol y Luna was amazing. Restaurants OYO in Lima were very good, as were the markets. If you are able, hike to the gate as well with a guide. Enjoy! And drink the tea - it helps with everything.