Can't start Django server

When I have made a new directory and entered it, I used following commands in order to start a django project:
django-admin startproject mysite
cd mysite
py runserver

And this is what happened:

Performing system checks…

System check identified no issues (0 silenced).

You have 17 unapplied migration(s). Your project may not work properly until you apply the migrations for app(s): admin, auth, contenttypes, sessions.
Run ‘python migrate’ to apply them.
November 22, 2019 - 15:11:58
Django version 2.2.7, using settings ‘mysite.settings’
Starting development server at
Quit the server with CTRL-BREAK.
Exception in thread django-main-thread:
Traceback (most recent call last):

UnicodeDecodeError: ‘utf-8’ codec can’t decode byte 0xe8 in position 5: invalid continuation byte

When I type in my browser I’m getting an error instead of loaded site.

To find more about error, check out your command line. If you are unsure about what made the error: checkout my guide on setting up Django correctly in a local environment.