Data and Maps

Going out on a limb - I need some help plotting data (symbols specifically) on a U.S. map by cities in Excel to show what areas are impacted most by a virus and how it changes over three months. I have tried several ways, and I'm having a hard time. I started with just adding states with the cities because Excel won't allow just cities to be mapped; when I did that, it wouldn't show the location of the cities. I then added the latitude and longitude of each city to make it more specific, but it's so precise you cannot see what the data means. I want to do a bubble chart of some sort but trying it that way did not line up correctly. I must be doing something wrong I'm not sure what.