1. Buy a radio first, pocket isn't for everyone. I love it. Get a sim, practice.
2. This one kinda depends on what they've done or can do in relation to RC or electronics.. If they are comfortable with soldering.
I would still say get an Air65 and some analog goggles first. It isn't the best for outdoor, but it'll do just fine. And is so great at indoor.
If they have to build, then a strong frame is best to start with I think, for sure 3.5" or smaller though. It isn't fun having to change arms or frames all the time. I don't think building a tinywhoop is for everyone. But it would be pretty cheap compared.
Just my thoughts. If I am having this conversation face to face, I would be offering help as well if they were to build or whatever. There were a lot of hurdles of just information that I had to figure out or lookup.. THANKFULLY the community is helpful.