Google Office products and Google Drive are free to use, and you have an unlimited amount of space you can use as a Bmail user while enrolled as a student (upon graduation, alums keep email access, but they no longer have access to Drive). You can learn to use Google Docs and Google Drive in LinkedIn Learning.
If you are completely new to Docs/Drive, it is recommended that you go through the Essential training tutorials first. They contain all you will need to get started and get comfortable with Google Docs and Google Drive:
Google Docs Essential Training
Google Drive Essential Training
Google Sheets Essential Training
In addition to the ones listed above, there are many other courses available in LinkedIn Learning that you may want to check out. There are tutorials available for users of all skill levels.