Hi leamaps,
The trainings I mentioned are helpful to me. They are broken up into segments, so you don't have to do them all at once, so I recommend them. One thing I learned from getting a GIS certificate at Cal Poly Humboldt (5 full semester courses) is you have to develop a sense of curiosity, and be willing to noodle around in the programs ( ArcMap, ArcGIS Pro, ArcGIS online) and esri help pages to solve your problems. You have to let go of the single-minded pursuit of solving your immediate problem, and instead use it as a focus area for learning about the subject. You will also gain a deeper understanding of how to use the programs. They were, after all, built by humans, but most humans don't think and act exactly alike, so you gotta learn the dance steps.
With regard to the vector tile web map, you are right! First we made a basemap of a number features on ArcGIS Pro and published it as a vector tile map on AGOL. Then, next step, we took features which were editable and published them onto AGOL as feature layers. Lastly, we we loaded the basemap from AGOL onto a new map, and then we added the editable feature layers. Then we published that map onto AGOL for future use with Field Maps so we can collect data in the field.
PS the new Field Maps Designer App is really cool.