Which watch is compatible with iPhone 5SE?

Any Watch is compatible with the iPhone SE (there is no such thing as a 5SE).

All Watches have GPS for geographic tracking, the GPS + Cellular also has a cellular radio so you can a connection even if you are not near your iPhone or WiFi. You pay your service provider for this connection.

Apple Watch - Compare Models - Apple

Apple Watch - Carriers - Apple

With the GPS only watch you need your phone near to make calls. With the GPS + Cellular, you do not your phone near to make calls. The GPS + Cellular version requires an iPhone 6 or later running iOS 12. The GPS only version will work with iPhone 5s using iOS 12. the same applies to the Watch series 3. Buy the best watch you can afford that meets your needs.