Hi Rick,
Welcome to our community! 
For this game, there is a simple solution: anchors.
https://docs.unity3d.com/Packages/com.unity.ugui@1.0/manual/UIBasicLayout.html
The CanvasScaler might also be interesting for you:
https://docs.unity3d.com/Packages/com.unity.ugui@1.0/manual/script-CanvasScaler.html
See also:
- Forum User Guides : How to mark a topic as solved