Crucial? Not at all. The only crucial things you need are curiosity, the ability to Google shit, and the understanding that the job is figuring shit out and knowing how to do that, rather than knowing how to do anything in the first place.
I've only had one colleague who does online mentoring, I think he used codementor.io but not 100% sure on that. You gotta realize that in our field good teachers are few and very far between, many of us fit the awkward introvert stereotype well and those who don't have no pedagogical training, that's why blogs and YouTube are the best resources for us. Spending time finding a good mentor is not certain to pay off and has a much higher effort cost than just scrubbing through YouTube for a while until you find a good channel.
As for industry insight, you're mainly gonna be interested in what technologies are hot right now and which are being discarded, again YouTube is fine for doing research here. You can also go to code meetups and just ask around, all the big cities used to have them semi frequently before Covid, don't know if it's back yet, see previous point about googling things.