Can I view my phones system without an activated sim?

I am purchasing a refurb 9a for myself and want to give my husband a refurb P6 I never activated or set up . I tried to contact Pixel chat support to ask my questions but the site wouldn't let me get to a chat option, so here I am...🙄

Can I view the phone's system and settings before the phone is set up and the SIM activated? I don't really remember the phone's specs or features so I hoped I could "open" the phone and explore it before activating a sim and transferring data.

When I power it up and turn it on, it asks if I want to transfer files and data but has a "don't copy" option.

What happens if I tap "don't copy"...? 🤔Do I have the opportunity to transfer data at a later time?

I am quite functional with a phone and a PC except when something goes awry and I have no idea what to do without googling for help. Consequently I also have a near paralyzing fear 😱 of choosing an option that takes me down a path of no return and/or loses precious data.

My husband will be switching from an iPhone SE 2020 to the Pixel and I've heard there can be issues transferring data from an iPhone to Android. However, he has very little to transfer - just photos and some contacts. I need to make sure his phone is backed up but that's something else I don't understand.

Will his data transfer directly from the iPhone to the Pixel or is it transferred from backup on an iPhone " cloud" which I assume is different than an Android cloud?

P. S. I guess I have the same questions about viewing my P9a before actually setting it up and activating its SIM. TIA