As I used to not write documentation, I must now do some deep digging to find out how to make it work, almost 10 years (!!!) after.
First get the relevant Python version (as I used Django 1.8.x the documentation says its compatible with Python 3.5)
pyenv install -v 3.5.10
pyenv virtualenv 3.5.10 DjangoMap3.5
pyenv local DjangoMap3.5
.python-version file at the root of the project now contains the name of the related pyenv.
As everything changes, you must install the requirements this way (check by yourself don't ask me why) :
pip install --trusted-host pypi.org --trusted-host pypi.python.org --trusted-host files.pythonhosted.org -r requirements.txt
python manage.py migrate
python manage.py createsuperuser
python manage.py runserver
I made some save of my old travel DB, just find it and replace the SQlite file as I used it in production (lol). Same for the media, the save is in the same place on gdrive.