Which cloud DB to use for the web application? [closed]

I am new to web application development. I want to use django for web application. I am trying to store the sensor data in cloud DB and read that data into my web application, Can someone suggest me if there is any cloud DB that we can use free or with low cost? I need to store below 1GB of data, and at least for 3 years.

Is there any option to start free and scale up as needed? This is for non-profit project for community, therefore, we are looking into the low cost set up.

Appreciated for all your advise.