From the cruise terminal, you could hire a cab driving to the Zhan Bridge, which isi one of the must in Qingdao. The journey will no more than 4km, so you could arrive there in 10 minutes by cab. The bridge is constructed on the sea, so you could have a very good view there. See more on this page: https://www.travelchinaguide.com/attraction/shandong/qingdao/zhan_bridge.htm

Then, you could walk up along the Zhongshan Road, which is a time-honored commercial street of Qingdao. Finally, have a local dinner and back to the terminal.