I am new to ArcGIS Pro and geospatial data in general. I have downloaded settlement extents data from https://grid3.org/. I had naively thought the data would display the population in a heatmap like manner, such as from green(lowest population) to red(highest population). But this is what I have
This is how the attribute table looks like
My two questions are:
What would the process in ArcGIS Pro to create a population heatmap?
How to avoid the settlement extents covering the countries boundaries ?