How do I change my Apple Watch face to another face?

You need to open the iPhone that your Apple Watch is paired to. Then, on the iPhone, open the Watch app and tap Watch Gallery at the bottom of the screen. From ther, you can look at all the different watch faces and select and customize the one you want. This link offers more instructions.

Customize the watch face - Apple Support

FYI - you can also select a new watch face right from your Apple Watch. Instructions are in the link I offered.

Adding an Apple Watch face is effortless and quick. Follow the steps discussed below to get started:

On iPhone

1. Access the Watch app on your paired iPhone.
2. Navigate to the Face Gallery menu.
3. Here, you can select any of the available faces.
4. Choose a face of your liking to proceed.
5. Every face features a ton of customization options.
6. Depending on the face you’re customizing, you can choose colors, symbols, and dials.
7. Scroll down, and you can allocate a series of Complications to the chosen Watch Face.
8. Complications are small icons that provide quick access to apps or data. Users can add or remove them based on preferences, giving complete control over available information.
9. Once set, click Add to save.
10. Your Apple Watch face will be automatically changed.

On Apple Watch

1. Tap and hold the existing Watch Face.
2. Swipe left until the (+) icon appears → Tap the (+) icon.
3. Scroll through the available faces. Here, you can tap the watch face’s thumbnail and scroll down to learn what the watch face entails.
4. Once you find your preferred face, select Add or Add Face to proceed.
5. Here, you can swipe left and use Digital Crown to scroll through the styling options available for the watch face.
6. Users can customize the watch’s face background color or choose from analog and digital time display styles.
7. Swipe left to go to Complications. Here, depending on your watch face, you can customize weather, activity, or other info.
8. Once ready, press the Digital Crown to apply the face.

Send your feedback to

https://www.apple.com/feedback/watch