Hi
Apple Watch Series 3 (GPS + Cellular) models
Apple Watch Series 3 (GPS + Cellular) requires an iPhone 6 or newer model, running the latest version of iOS. It is not locked to any specific carrier and has a built-in eSIM that copies information from the iPhone's SIM card.
The built-in cellular features require a carrier plan for your iPhone that specifically includes support for Apple Watch, including the carrier activating the device on the plan.
Cricket is not currently listed by Apple as a carrier that offers compatible service plans:
Apple Watch - Carriers - Apple
I suggest that you contact Cricket to ask about their plans for supporting Apple Watch Series 3 (GPS + Cellular). You can also monitor the page linked above for further carriers being added over time.
If you do not wish to enable the built-in cellular feature for now, then Apple Watch Series 3 (GPS + Cellular) models can still be paired, set up and used for other features whilst skipping the steps to activate cellular, in which case they act like the Series 3 GPS-only models.
The built-in cellular feature can be enabled later, if and when you are using a compatible service plan on your iPhone.
Series 3 GPS-only models (and all other Apple Watch models)
Apple Watch Series 3 (GPS) and all other Apple Watch models can be used in any country in conjunction with an iPhone 5s or newer model of iPhone (running the latest version of iOS) and a service plan for the iPhone from any carrier.
More information:
How to use your Apple Watch without your iPhone nearby - Apple Support
About Bluetooth, Wi-Fi, and cellular on your Apple Watch - Apple Support