It's easy to use tutorials and video tutorials to learn Blender 3D software simply and effectively. But for a better understanding of how this software works and for more technical requirements, I recommend you to read the user manual available in HTML and EPUB format for version 3.4 on this official webpage.
I prefer to read files in EPUB format, this manual is quite large with a size for EPUB format of about 207 MB open with sumatra pdf reader the on my desktop PC.
