Hi
Apple Watch Series 1 and Series 2 models state "Series 1" and "Series 2", respectively, on the back of the watch case. 7000 series refers to a type of aluminium used in various first generation, Series 1 and Series 2 models.
To check the model - along with service and support coverage details - you can enter the serial number here:
https://checkcoverage.apple.com/
To locate the serial number:
Find the serial number for your Apple Watch - Apple Support
Apple also offers the following resource for identifying your Apple Watch model:
Identify your Apple Watch - Apple Support