How do I sign into my iPad with my iPhone Apple ID but make It where NONE OF MY texts or phone calls are synced to the iPad?

On your iPhone

1. Settings > Messages > Text Message Forwarding > [Select iPad] [Disable]
2. Settings > Phone > Calls on other devices > [Select iPad] [Disable]

By default, a number of iCloud services will sync when you sign in with the same Apple ID. To prevent this syncing on your iPad, you will need to disable syncing on those services you don't want on your iPad.

Settings > Your Name > iCloud, then move the slider to the left for those services that you don't want synced.

However, SMS text and phone calls are not provided by Apple, but from your cellular voice provider. If both of your iOS devices are using the same phone number, then you will need to contact them about how you would go about disabling (if possible) syncing between these services.

If iPad uses the same Apple ID as iPhone then you may disable Calls and Text messages from getting forwarded to iPad.

Watch the GIF below for complete process.

iPhone SE iOS 13.4.1

iPad Pro iOS 13.4

You don't. Using the same Apple ID on both devices, that's a normal behavior.

Regards

Giulio