Office 365 QuickStart Guides:

https://support.microsoft.com/en-us/office/office-quick-starts-25f909da-3e76-443d-94f4-6cdf7dedc51e

Office 365 in Depth:

https://support.microsoft.com/en-us/training

Outlook:

https://support.microsoft.com/en-us/office/outlook-training-8a5b816d-9052-4190-a5eb-494512343cca?wt.mc_id=otc_home

Teams:

https://support.microsoft.com/en-us/office/microsoft-teams-video-training-4f108e54-240b-4351-8084-b1089f0d21d7?wt.mc_id=otc_home

Word:

https://support.microsoft.com/en-us/office/word-for-windows-training-7bcd85e6-2c3d-4c3c-a2a5-5ed8847eae73?wt.mc_id=otc_home

Excel:

https://support.microsoft.com/en-us/office/excel-video-training-9bc05390-e94c-46af-a5b3-d7c22f6990bb?wt.mc_id=otc_home

PowerPoint:

https://support.microsoft.com/en-us/office/powerpoint-for-windows-training-40e8c930-cb0b-40d8-82c4-bd53d3398787?wt.mc_id=otc_home

OneDrive:

https://support.microsoft.com/en-us/office/onedrive-video-training-1f608184-b7e6-43ca-8753-2ff679203132?wt.mc_id=otc_home

OneDrive Icons and its meaning:

https://support.microsoft.com/en-us/office/what-do-the-onedrive-icons-mean-11143026-8000-44f8-aaa9-67c985aa49b3

SharePoint:

https://support.microsoft.com/en-us/office/sharepoint-video-training-cb8ef501-84db-4427-ac77-ec2009fb8e23?wt.mc_id=otc_home

SharePoint syncing:

https://support.microsoft.com/en-us/office/sync-sharepoint-files-and-folders-87a96948-4dd7-43e4-aca1-53f3e18bea9b