I would make Chengdu a food extravaganza inbetween your sightseeing.
Rabbit head is a big think also they have a cold hot pot chua儿 thing. Chengdu snacks are amazing.
There is a Happy Valley Amusement Park, an Ocean Park adding to the above spots.
Keep in mind that Chengdu is huge but taxi fares are fairly cheap. Subway system also brings you a certain convenience.
People in Chengdu are superfriendly are very happy to help.