Where can I find manuals, documentation, examples or tutorials?

The manual is available as online help in the menu
Help -> PTV Visum Help
Additionally with the same contents as PDF in:
Help -> PTV Visum manual
c:\Program Files\PTV Vision\PTV Visum 2021\Doc\Eng\PTVVisum2021_Manual.pdf
This path contains also additional documentation.

Example files are availalbe in:
Help -> Examples
c:\Users\Public\Documents\PTV Vision\PTV Visum 2021\Examples\
https://www.ptvgroup.com/en/solutions/products/ptv-visum/knowledge-base/faq/

Tutorials are available in:
Help -> Examples
c:\Users\Public\Documents\PTV Vision\PTV Visum 2021\Quickstart Tutorial\
c:\Users\Public\Documents\PTV Vision\PTV Visum 2021\Tutorials\

Additionally you can watch recorded webinars here:
https://www.ptvgroup.com/en/solutions/products/ptv-visum/knowledge-base/webinars/

Training opportunities can be found in:
https://www.ptvgroup.com/en/training/courses/