How can I store and retrieve objects from the real-time database

[tatiang]

If you haven’t searched the forums or watched tutorial videos, start there. If you have, post a link to your project or screenshots of your blocks and explain what happens when you preview your project and what you want/expect to happen.

These may be helpful:

Storing data to be reflected on google sheets

If you want to graph things in Google Sheets, why not store your data directly in Google Sheets? If you want to use Firebase, you can do that with cloud variables. Here are some examples of that: You don’t need a special block for accessing Firebase data… you just use the blocks in the Variables drawer. The name of the cloud variable is the path to the data in Firebase.

Cloud Variables - Save User Data to the Cloud in Thunkable Drag and Drop UI