If I use Indeedee's "Expert Nurturer" attack, do I have to declare what card I am getting before I look through my deck?
No. You can look through your deck before deciding on which Pokemon to evolve.
Source: TPCi Rules Team (2023-03-30)
Can I use Indeedee's "Expert Nurturer" attack to evolve a Pokemon on the first turn of the game, or on the first turn that Pokemon came into play?
Yes, it can.
Source: TPCi Rules Team (2023-03-30)