First time buying a smartphone. Could really use some help/advice. [View all]

For some weird reason I'm really anxious about this. I've waited too long, and now it's hard to even function in society without at least the cell phone part of a smart phone, and emergencies and disasters happen on a daily basis, and everyone should have a camera in case some gross injustice needs to be caught on video.

But then I just remind myself that if Louie Gohmert can use a smartphone, I am sure I can figure this out. I'm almost ashamed to take up any DUers valuable time on something I should have learned 15 years ago and apologize in advance. Many of the helpful articles online assume that the reader has a certain amount of knowledge that I really don't have, so I'm pleading for some real basics here:

I think I want to get an Android (especially interested in the Google Pixel 4a). My idea as of now is to order the new, unlocked phone directly from a seller.

1. Once I actually receive the phone, will it walk me through the process of getting it activated and connected to a carrier and purchasing a plan, or do I have to go find a particular store (we have several Verizon stores in my town) and sit down mask to mask with somebody and go extensively through different plans and options--something I would ordinarily do but am trying to avoid until I'm fully vaccinated?

2, Or do I have to have a plan with a carrier set up in advance before getting a phone? (I currently only have a landline phone).

3. This SIM card seems really important and is referred to in many of these articles. Since this will be my first phone, I don't have anything to transfer to a new phone. But does a SIM card come with every new phone? Or is that something I received from the carrier (Verizon, ATT&T, T-Mobile, etc...) and insert into a new phone?

4. Is there anything obvious that I'm missing or forgetting, or can you tell from the three questions above that I really have barely a clue what I'm doing?

Am I approaching this wrong? Should I just brave the local smartphone store and let them set me up?

Huge thanks and gratitude in advance for any advice or help!