TTC newbie

I’m new to TTC and looking for some advice. I’m wondering when in my cycle should I start using OPKs? Also I’ve read that when tracking BBT you should always take your temp first thing when you wake up, before you even get out of bed. Maybe a silly question but does it matter what time of day it is? Sometimes I’m up for the day at 2am, sometimes I don’t get up until 6am. I am on prenatals and I track my CM. Any tips or tricks are so appreciated