Django is very popular because it is written in python because of which it is very easy to learn. Django is also very powerful, as it powers some of the biggest websites like Instagram, Spotify etc. Django is also very popular because it's very easy to learn and use and is in high demand. It is also very scalabale, which means that it can handle large number of requests.
If you wish to learn more about Django you can take this end to end Django certification course.
If you just wish to get your feet wet and try Django out you can follow this Django tutorial.