Installed versions of Python

[snippsat]

You could install newer version look at Python 3.9/3.8 and pip installation under Windows
Visual Studio Code is more geared against Python,take a look at VS Code from start

So am I safe in assuming I am using Python 3.7.1? Will the version 3.5 in AppData be a problem?

It's no problem to have many version i have a lot from python.org and Anaconda/Miniconda...ect.
For main version used most i like that python and pip point to that version(Windows Environment Variables Path) for easier editor setup and stuff,
then can use py to call other version.
Example same in cmd here use cmder(recommend).

G:\div_code
λ python -V
Python 3.9.5

G:\div_code
λ pip -V
pip 21.2.4 from c:\python39\lib\site-packages\pip (python 3.9)

G:\div_code
λ py -0
Installed Pythons found by py Launcher for Windows
 -3.9-64 *
 -3.8-64
 -3.7-32
 -3.6-32
 -3.5-32
 -3.4-32
 -2.7-32

G:\div_code