Google Drive & Docs
Your Google applications can be accessed by clicking the top right Apps button as shown below.
'My Drive' is your personal drive, it is where you can find all your own uploaded files and folders.
'Shared drives' are essentially spaces shared with others. You have access to the same files and folders within these spaces and may be able to upload to them to share.
Google Docs, Sheets and Slides
Google docs, sheets and slides are the Google versions of Word, Excel and Powerpoint. They function really similarly and are straightforward to use. These can be created directly from Google Drive by right clicking which brings up a menu and gives you a choice of the three. You can also open and edit files from Microsoft Office in Google but for Powerpoint Presentations, you may lose your animations and transitions.