Regarding building a website

[snippsat]

did you mean to say should i execute these commands from cmd prompt one after another irespective of location of python on my computer?

Yes you can choose what folder you want,and you most read link that i posted.
The first step is that python and pip command most work form anywhere in cmd/PowerShell or cmder i use.

If use 3.8 just the same,but then it point to 3.8.

# Test python
C:\
λ python -V
Python 3.7.3

# Test pip
C:\
λ pip -V
pip 20.0.2 from c:\python37\lib\site-packages\pip (python 3.7)

When this work can make a virtual environment from any folder you want.

# Make
E:\div_code
λ python -m venv web_env

# Cd in
E:\div_code
λ cd web_env\

# Activate
E:\div_code\web_env
λ E:\div_code\web_env\Scripts\activate

# Install django
(web_env) E:\div_code\web_env
λ pip install django
Collecting django
.....  
Successfully installed asgiref-3.2.7 django-3.0.4 pytz-2019.3 sqlparse-0.3.1

# Test that it works
(web_env) E:\div_code\web_env
λ python
Python 3.7.3 (v3.7.3:ef4ec6ed12, Mar 25 2019, 21:26:53) [MSC v.1916 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import django
>>>
>>> django.__version__
'3.0.4'
>>> exit()
(web_env) E:\div_code\web_env