4G connection

I have done a lot of research on setting up the infotainment system and i have also read a lot of posts that the system is not as great as others on market. I agree as i had a 2011 vehicle that had a more robust and sophisticated system than this 2018. I am hoping someone with expertise in this can assist me as the dealership has a bunch of old guys that don't get the electronics and they have one young tech, but he was not there when i picked up vehicle to provide me the step by step i was hoping for. Alert: I am not at all technical, but am able to navigate around and figure out new tech, so frustrating you seem to have to have a degree to figure out what should be a simple set up if the user interface was just a bit more intuitive.

So, my screen shows "4G" in upper righthand corner with all bars showing. I have set up my home WiFi, so sometimes updates happen overnight, etc. I have a SIM card which came with the vehicle, which i assume is why it is showing the 4G indicator on the screen.

My questions:
Is the weather update only possible with a SIM card in place?
Does the SIM card need to have a data plan attached to it? If it is saying 4G and showing bars, does that not mean the SIM card is active?
Are there some things that are done via satellite?
I have SirriusXM, does that have any features that provide information into the infotainment system (such as traffic or sports updates - that is what was on my 2011 vehicle)?
Can i plug my phone in (that has a data plan) and piggyback (i.e. tether?) to get data for my infotainment system?

Thanks for any insights you can provide as I am just not certain why so much reliance on a stand-alone data plan to get what is essentially pretty basic features for a current infotainment system.