peewee vs django for DB processing
This is entirely opinionated, but I think you should use Django for the entire thing. It's not that I don't like peewee. On the contrary, it might very well be a better ORM. But I have a few reasons I think you'd prefer the Django ORM:

I think the Django ORM is more intuitive for beginners, and covers most use-cases pretty well. In the future, when you feel comfortable with Django in general and the Djagno ORM, it will be easier to learn how to use peewee and see if you prefer it over the default
There's a larger community of Django users that don't use peewee over those who do. That means more people being able to help you (and here at SO) and an easier time finding out the answers to any question you will have.
I think peewee is more SQL-y in it's syntax, which I find is easier to understand after you learn a little SQL, while using Django's ORM doesn't require vast SQL knowledge besides the very basic stuff

So peewee is a very viable option, but I think you shouldn't start using it straight away, not before you have any problems with the default.
Working on a python & Django project with mysql (newbie) 
Trying to figure out if it is preferable to use peewee in the python DB part & Django models in the Django forms or go ahead and use Django for the entire thing
Related answers claim that Django is high overhead but could not find a base for that assumption
Thanks,
Shimon