...
Open your web browser and navigate to your SharePoint site.
Select the Documents tab in the left side-panel and navigate to the folder you want to create the document in.
Click New in the top toolbar and select the type of file you want to create.
...
On your computer that is synced to the SharePoint, open File Explorer or Finder.
Find your SharePoint local copy
Windows: Under University of Connecticut in the left sidebar, you will see a folder named after your SharePoint site. This is your local copy of the site. Open this folder.
Mac: Click OneDrive- Shared Libraries… in the left side-panel.
Navigate to the folder you wish to upload the file to, and drag-and-drop the file into that File Explorer window. You may also copy-and-paste the files it into the SharePoint folder.
...
Create a new Office file (e.g. a Word, Excel, or PowerPoint file).
Click the Save icon in the top left.
Click More Options.
Select Sites - University of Connecticut and choose the SharePoint site you wish to save to.
Use the file explorer to navigate to the location you want to save the document in that SharePoint site.
Click Save.
...
Open your web browser and navigate to your SharePoint site.
Click Documents on the left sidebar.
Use the file explorer to navigate to the folder you want the file uploaded to.
There are two ways to upload content:
Click Upload and choose the appropriate option.
Alternatively, drag-and-drop the file from your computer into the SharePoint window.