e-bike dashboard

Hi, i have a school assignment to make a android app that wil lserve as a dashboard for e-bike showing different parameters in real-time. I'm am familiar with sockets somewhat other than that i'm a complete beginner. I have set up a server on a ESP32 module that has built in loopback. The app has to send a string to the server which will be sent back and shown in the appropriate textview element. The string format is the following: the first character is the label of the correct textview, the last character is e.g. e or n, something that the app will know is the end of the current string, in-between is the value. Any tips, examples, tutorials are very welcome. Thanks