You can put marker where you want. If you clicked any place for a long time, marker is added and the title is the address.
You must open Google_map_api. This file path is "Res->Values in Android Studio. There is a link in Google_map_api. Open the link at follow steps. After that Google gives an Api_Key. You must copy the key. Then replace Your_Api_Key at api key in Google_map_api.