I sort of backed into being a fan.
In the 60s and 70s when the original was shown on PBS, I didn’t always live in areas that had PBS. So, I just never got interesting in the original Dr. Who.
A few years ago, I watched a short-lived series, Special Unit 2. It was of the Men in Black genra, policing aliens. Then, I read of Torchwood, which was similar, so I watched it. Torchwood has numerous references to Dr. Who, so I got a general idea of what Who was about.
Then, SciFi Channel was running the ‘new’ Who with Eccleston. I started watching then, continued with Tennant, and Smith.
I also liked the childrens’ version called The Sarah Jane Adventures. Years earlier, Sarah Jane Smith, played by Elisabeth Sladen, was a companion and appeared with several of the old Doctors.
Torchwood was often truly awful.