Visit the official Google support here.
To create a new file:
1. Click the blue "New" button in the top left, under the BPS logo.
2. Choose which type of file you want to create. Google Docs is a text file, Google Sheets is a spreadsheet, and Google Slides is a presentation.
3. There are other types of files you can create by clicking more, such as Google Forms (quizzes) and Google Drawings.
You can create all the same files by right clicking in open space and select your desired file type.
To change the name of a file, click where it says "Untitled document" and type in the name. Press enter to confirm. After you have made an edit, such as changing the name or writing some words, you do not need to save as Google automatically saves for you.