My apple tv picture is way outsize and no longer fits on my tv screen. How do I resize it to fit?

Hello!

This article may help you:

Adjust video and audio settings on Apple TV - Apple Support

Just in case, check if your TV's settings are causing this.

If you're seeing things "zoomed" you may have selected a movie scene or other from your remote control by mistake.

There’s also an accessibility function to zoom in on the Apple TV box.

Settings﹥Accessibility﹥Zoom﹥…

Possibly that was accidentally enabled through the Accessibility Shortcut (triple-click Menu or Back)? Users can set which accessibility functions to include in this shortcut. All functions unchecked would disable the shortcut.