To map things, you will need to enrich your data with what the map needs to display this info.
A good place to start is the Mapping section of docs. For example, there are some built-in lookups in Splunk for countries and US States. Depending on your country format in your data, you might need to add additional columns (aka enrich your data) with the relevant geo-info the maps visualization needs. Reviewing the docs for this should get you on the right path.
Another place to check out is the Splunk Dashboard Examples app. It has a lot of good visualization examples with dummy data that you can copy from. 😀
