Learning Python first step in jupyter notebook

Basically, Jupyter note book means viewing local files in the browser, right?
but why is the browser indicating ‘not connected’, sometimes not trusted?
I am an absolute beginner at this subject.

This is from the command prompt

How can I understand this below text?

(base) C:\Users\pc>D:

(base) D:>Test directory\codes
‘Test’ is not recognized as an internal or external command,
operable program or batch file.

(base) D:>cd Test directory\codes

(base) D:\Test directory\codes>jupyter notebooks
usage: jupyter [-h] [–version] [–config-dir] [–data-dir] [–runtime-dir] [–paths] [–json] [–debug] [subcommand]

Jupyter: Interactive Computing

positional arguments:
subcommand the subcommand to launch

optional arguments:
-h, --help show this help message and exit
–version show the versions of core jupyter packages and exit
–config-dir show Jupyter config dir
–data-dir show Jupyter data dir
–runtime-dir show Jupyter runtime dir
–paths show all Jupyter paths. Add --json for machine-readable format.
–json output paths as machine-readable json
–debug output debug information about paths

Available subcommands: bundlerextension console dejavu execute kernel kernelspec lab labextension labhub migrate
nbclassic nbconvert nbextension notebook qtconsole run script server serverextension troubleshoot trust

Jupyter command jupyter-notebooks not found.

(base) D:\Test directory\codes>