Google Maps vs. Widget vs. TextShortCode Confusion

I am having some confusion between the implementation of Google Maps as a plugin, widget or through a text box and using the shortcode to add it. I installed the Google Maps Plugin, and was creating a section on UpFront to place the map and on the left navigator there is a Maps icon which I used to add a map. I quickly found out that this is not the plugin and something else. I also created a post and added the short code there and then added it through a text box on the section in upfront.

So first question, do I have to create a post to get the short code?

The other thing is on the Google Maps plugin there is custom fields. Where will those fields appear? I labeled them and they do not appear in the post or page when adding a map.

Ultimate goal is to place all the map locations on the main page in the Google Map section of upfront. I saw some information about tags but where do you place those? Do I assume the those short code goes in the post as well as the map shortcode?

This is very confusing.