That transition period is definitely easier if your diet is already pretty clean & you're somewhat metabolically flexible.

Fasting and carnivore go well together but if you're not already fasting, I'd add it later. It just sort of happens for most people on carnivore.

I've seen men/boys do carnivore a little better than women. For some reason women seem to feel better with a little carbohydrate strategically added in. We're all slightly different & in my mind it doesn't make sense to be super strict with your diet. This usually happens months after being strict with it by the way.

For the record, I have carnivore meals & I eat a lot of meat but I'm no longer carnivore. I did beef & water for the first month & then added other meats, dairy, herbs & spices, coffee. I did this for a year before adding refined starches, sugar & fruit back in.

The only things I avoid now are seed oils & fibre.