A tutorial showing how to do something similar is
How to broadcast a GPS location and share the information on a map with others in real time..CloudDB The example uses the MIT CloudDB. This could be replicated using a Google Sheet.
A method showing how to track multiple individuals using a CloudDB is
Social Distancing ... a CloudDB / Location Marker Tutorial The main parts of this example seem pretty close to what you want to do.
Possibly the above links. What have you tried?
Here are possible parts of the solution:
Here are some resources to help you learn to use the AI2 tools. A very good way to learn App Inventor is to read the free Inventor's Manual here in the AI2 free online eBook http://www.appinventor.org/book2 ... the links are at the bottom of the Web page. The book 'teaches' users how to program with AI2 blocks.
There is a free programming course here http://www.appinventor.org/content/CourseInABox/Intro and the aia files for the projects in the book are here: http://www.appinventor.org/bookFiles
How to do a lot of basic things with App Inventor are described here: http://www.appinventor.org/content/howDoYou/eventHandling .
Also look here App inventor español. Offline. Tutorial. Ejemplos. Instalación. Códigos. Juegos. Curso gratis de App inventor. and here Tutorial Index | imagnity for more tutorials.
Learn about components Component Reference
and visit the Library The MIT App Inventor Library: Documentation & Support Help>Library on the MENU