keep getting 'encoding' error

[snippsat]

When I dble-click python.exe I get a cmd window and python starts and gives me a >>> prompt and print("hi") returns hi ok so python seems to be installed. But I dont see my PATH variable has been set so any idea what it should point to?

You have to start cmd(Command Prompt).
Here you type python and Python should start,also pip -V to check pip.

Is it completely forbidden here?

No,but we usually prefer code in code tag,i am gone post a picture of cmd(command prompt),
because i don't even think you know what it is.

cmd(command prompt) is an important part here you do all install with pip.
So if you followed my link about install 3.6 it should works as in image.
Here tutorial about cmd(Command Prompt).