Flask not responding after installation

[Tamara Berger]

It seems I can’t progress a single step without encountering a wall.
I’m trying to build a webapp with flask. I installed flask. I followed
the workbook-provided prompts, which should have resulted in a flask
confirmation. Nothing happened. Any ideas what’s gone wrong:

Last login: Thu Jun 14 13:31:25 on ttys000
Tamaras-iMac:~ TamaraB$ cd Desktop/Web
-bash: cd: Desktop/Web: No such file or directory
Tamaras-iMac:~ TamaraB$ cd Desktop/Webapp
Tamaras-iMac:Webapp TamaraB$ python3 hello_flask.py
Tamaras-iMac:Webapp TamaraB$

Thanks,

Tamara