Hi ashleid,
Screen Time on the Apple Watch can be enabled if a family member has set up your Apple Watch on your behalf. This would be the case if you do not have your own iPhone with which to set the watch up. Once set up this way, the family member who set up your watch would be able to manage Screen Time. You can get more details on how this works in the Apple Support articles listed below:
If you did not have a family member set up your Apple Watch, do not hesitate to respond back. If you do, please let us know where you are seeing that Screen Time is enabled on your Apple Watch, and what impacts you're noticing it have (for example, are you being prevented from accessing certain apps or content from the watch?).
Best!