MS Office to GSuite
Microsoft Office files are able to be opened via the GSuite apps such as Google Docs, Google Sheets, and Google Slides. After an Office file is uploaded into your Drive or is opened on a Chromebook, Google Chrome will automatically open the assigned application for that specific file type.
Word = Docs
Excel = Sheets
PowerPoint = Slides
Some formatting issues may occur but otherwise, you should have full access to the files.
While in the GSuite applications, you can also work in the opposite way by clicking on File, then Download to have your Google files in a Microsoft Office format.
Auto Conversion of your MS Office files
Google Drive offers the ability to auto-convert any Office files to the corresponding Google file.
By default this is not enabled but can be turned on through the Settings in Drive by going to your Drive, click the settings gear in the upper right and checking the box to the left of the Convert uploads to Google Docs editor format.
As mentioned above, please know that some formatting issues may occur by converting MS files to Google files. This occurs more in PowerPoint files than most others. You may also lose some animations and abilities in those files you once had such as formulas in Excel not translating over into a Google Sheet.