No, I'm afraid not - Apple Watch Series 3 (GPS) is not currently available to buy with an included Sport Loop.
When initially buying Apple Watch, Apple does not offer the option to mix and match cases and bands or to exchange or trade in included bands, whether in store or online.
Apple Watch is instead only available in certain preconfigured combinations of band and case. All models that are currently available to buy (in the US, for example) are detailed here:
Buy Apple Watch Series 3 - Apple
Certain bands are available to buy as a separate accessory. All Apple Watch bands are compatible with all Apple Watch models of the same case size (38mm / 42mm):
Buy Apple Watch Bands - Apple
If an included band is surplus to your requirements, then you may wish to consider selling it.
Change your Apple Watch band - Apple Support
Remove, change, and fasten bands