I need to install a new shower valve but have no experience sweating copper pipe. Is it possible to use one of the new plastic pipe materials/methods to connect? I would have to use plastic on both the inlet and outlet sides of the valve. Thanks in advance for any advice, thoughts, ideas.

You can use sharkbite to connect copper to cpvc and cpvc to the shower

The Shark Bite is expensive, may have to go to Ace Hardware or a plumbing supply it find them, but almost falls together and doesn't leak.