Hi aneeqa48,
We appreciate you reaching out through Apple Support Communities for help with the activity goals on your Apple Watch. We're glad to help!
We've got a great resource that explains exactly how to change your goals. You'll want to refer to the steps in the section titled, "Change your activity goals":
Use the Activity app on your Apple Watch - Apple Support
To be able to modify all goals, you'll want to ensure that your Watch is updated to the latest version of watchOS. Here's a guide to help:
Update your Apple Watch - Apple Support
We're here for you if you've got any questions.
Have a great day!