Can I freeze fresh made sauce?

One – yes.

Two – fresh canned frozen tomatoes?

You can freeze it, but when it thaws, you’ll see that the liquids and solids have separated a bit. It will come back together if you warm it up and give it a good whisking or, better yet, hit it with an immersion blender

What @thorninmud said. I freeze primavera-type sauces all the time, and the flavor holds, but the texture is never quite the same as if you were serving it fresh. It’s not any worse, just different, IMO.

I can’ really see why you can’t do that :)

Absolutely!