Adapting to expat life in a new country is always a challenge, and learning to speak the local language is one of the best ways to ease the transition. That being said, there is a growing community of English-speaking expats in Bogotá, so your family should still be able to settle in despite their limited knowledge of Spanish.
Have a look at our guide to dealing with culture shock in Colombia for more information on what to expect from your move.
Since Colombia is on lockdown, I would like to recommend my Spanish instructor (who is currently working from home, so you would have the benefit of one on one teaching).
Tel# +57 3153370133
Or on Skype: felipo.barbosa
I have been continuing my Spanish lessons online with him. He's very patient and breaks things down well. It's been a great asset in learning to speak like a local.