Newb Reloader Questions - 9mm

[NWIeng]

Alright reloader's, hoping you can help get me started.

I've got the basics coming in a week from now. Just a simple setup for now, lee hand press as I don't want a fixed garage setup. Going to be loading strictly 9mm for now. I've got some questions about the flaring of the case mouth and the crimping operations.

For flaring the case mouth, I've seen videos and read about how overflaring will wear the case out quicker and obviously underflaring would making bullet seating difficult and possibly crush brass if not flared at all. So my question is since I don't have past experience, does someone who reloads 9mm have a diameter to which to flare the case mouth to?

I'm just picturing that if I have a number to work with, then I can just take a caliper to the flared mouth to know when I'm right on. Does this sound like a decent mindset? Or is this strictly a 'looks good/test and see' issue?

Next, the crimping operation. Visually, how can you tell that you've properly crimped? Or is this die not really depth dependent?

Any and all help will be greatly appreciated! I'm getting really pumped to start saving some money, or at least picking up a new gratifying hobby.