Custom Map, or Canvas? (making a Kriegspiel board game clone)

[SteveJG]

Welcome George.

@George_Peterson

wondering if I could zoom in on one part of a very large canvas.

Probably not, at least while using the App Inventor Canvas component. Developers can zoom into a real map using the Map component and the map's tile set.

@George_Peterson

sprites that need to retain their position, and interact with each other, basically a custom map.

A Map or a game?. Here is one way to use a Canvas for a map AI2 Flat Map Tutorial

Otherwise how to use Sprites on a Canvas is explained in Creating Animated Apps

@George_Peterson

figure out how to using a canvas, or would it be easier to acquire an extension?

If you provide a more detailed explanation of what you hope to do, someone can provide specific advice. It is possible to make an annotated Map that can be zoomed using Polygons, that might be what you want to do.