I visited this WHS in January 2020. For those visiting by rental car like I did, the easiest way to park your car in a safe place is by heading to the underground Parking La Laguna.
The WHS is relatively small and basically spans from Plaza de la Concepcion to Plaza del Adelantado with a number of churches, chapels, monasteries, convents, an old tower and a lot of 17th and 18th traditional Canarian houses with open courtyards and wooden balconies. This WHS's layout is believed to have been the prototype for most of Latin America's cities and towns. In fact, it really reminded me of Lima which I had visited a couple of months before.
The Cathedral, adorned with tall palm trees and dragon trees, can now be visited for an expensive 5 euros (free audioguide) but not worth the entrance ticket in my opinion. Most traditional houses have been altered a bit too much and taken over by globalisation and consumerism (Starbucks, sushi shops, etc. just to mention a few). Those worth visiting, especially for their tiled courtyards, are Casa Alvarado Bracamonte (which now houses the La Laguna local council), the red stone facade of Casa Riquel and Casa de la Alhondriga for its rebuilt wooden balconies. The church and convent of St. Augustin and the Church and Monastery of Santa Catalina de Siena, with its grill keeping away the nuns from the rest of the world outside, are worth visiting but don't compare with world-class examples for example in Arequipa, Peru, or elsewhere worldwide.
I'm glad I visited San Cristobal de La Laguna (or simply La Laguna as it is known), however in my opinion, although worth visiting when in Tenerife or the Canary Islands in general, it does not possess enough OUV and it does not deserve its place on the WH list.