This is how I work. It might help you find your own errors.
Firstly install python 3 on your computer
https://www.python.org/downloads/
Secondly you need a code editor. I prefer to use geany
https://download.geany.org/geany-1.38_setup.exe
You need a python code linter. I use pylama
Open windows power shell as administrator and type pip install pylama
Set geany to use python
build > set build commands
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C:/ProgramData/Python/python -m py_compile "%f"
C:/ProgramData/Python/Scripts/pylama --max-line-length=800 --ignore=E722,W605,C901 "%f"
Then you just need to load all your python files.
Click compile. This will tell you any code that is not compatible with python 3.
Click full lint (f9 on my machine), will warn you of things to clean up.
other helpful commands in Geany.
Document > strip trailing spaces
Document > Replace Tabs with spaces (4)
Any errors, google is your friend, which will probably send you to a similar question on stackoverflow.
The hard bit is getting it work on both python 2 and python 3.
That just comes with experience and looking through any of my plugins source files, you will find lots of examples of hacks we got going on to accomplish that issue.
Then its just a case of turning on debug logs, loading your files. Crashing your box, fixing file, loading your files, crashing your box, fixing file.... rinse and repeat :)
And for skin xml files I use notepad++ with xml tools plugin added.
That will tell you any xml errors on save. Also can format code with pretty print.