Should I always use virtualenvs in Django?
Your question is:

Can I continue without installing it?

So the answer is yes.
The virtualenv is not a requirement to set up a Django project. Nevertheless, you will eventually use virtualenvs in the future when you are more aware of dependencies, so why don't you start to learn now how to use them?
A virtualenv is not the only solution to isolate your project's dependencies but is the most commonly used in Python developments.
I'm a beginner, and I'm learning Django for web development. So I want to know for my little test, should in always have a virtualenv or can I continue to learn without installing it? I've asked because in youtube Django videos, some instructors are installing it, and others aren't.