You have to step up and own your ignorance if you ever want to move past it.
Be kind and gentle. Don't be their best friend -- do be their best teacher.
If they discover you weren't right, then apologise to them just as you would in any other situation where you are wrong. What they learn off you is how to be a human, not how to be right 100% of the time.
[At the start, they only need cuddles, feeds and cleaning anyway so you have time to learn as you go]
Father of 3 preschoolers speaking. I'm sure there's more to come.
I've had to apologize to each of my kids more times than I can count. The benefit that I've seen is that they are all willing to apologize to me as well.
It seems to have worked well so far, but my oldest is just 18 and the sample size is small.
Part of what I mean is you want your kids to know that you'll be there for them and you always have their best interests at heart. You want them to rely on you like the sun coming up in the morning, and you want to be able to bear that weight. Stability breeds healthy kids who aren't anxious about sudden change.
But if you make a mistake, you have to show them that it's OK to back down and apologise. Because they will know when you're being unfair, or if you're saying one thing but doing another. You're not earning their respect and trust if you do otherwise.