SharePoint Document Library Tutorial

How to use Microsoft SharePoint

Upload, create, and manage files in SharePoint document libraries

Uploading Files into a SharePoint Online Document Library

Sharepoint Uploading multiple folders and files

SharePoint framework tutorial: Set up your development environment and Create web part using SPFx

SharePoint Framework Tutorial Part 1: Setting Up SPFx Development Environment

How to Set up SPFx Development Environment | SharePoint Framework Development Environment Setup