Although hotspots are used to aggregate results in popular birding locations, you should not ALWAYS use a hotspot while eBirding. If you went birding in a location that is accurately represented by a hotspot, then you should use that hotspot. If you were birding adjacent to a hotspot, or somehow birding in a way that isn't accurately represented by that hotspot, then you should NOT use that hotspot. You can create a new location, and either suggest it as a public hotspot or keep it as a personal location. The more specifically named the hotspot is, the more the birding included in your checklist should be restricted to the named location. If it is named "Intersection of 1st Ave x Broadway Blvd" use it for birding done at that intersection. Don't use it for a 5 mile walk passing through that intersection; instead use the one named "Broadway Blvd" for that longer birding experience.
The best way to choose an existing eBird location is to click the "Submit Observations" tab and then search for a county, state, province, or country by using the "Find it on a Map" search field. The map returned will likely have a bunch of red markers on it. Each of these represents an existing eBird hotspot. Simply click on the red marker to see the location name, which will appear in the box adjacent to the map. To choose another location simply click on a new marker. When you're happy with your selection move on by clicking "continue." Tip: if you can't get the map to work, make sure you've spelled the county correctly, and if all else fails leave county blank and simply use the tools to zoom in to your location from the state or province level.