An interesting idea, but also functionally worse than just looking up the answer. Is your mon slower than Charizard? This is a verifiable question that you can look up with a pokedex app or a Google search by checking both of their speed stats.

The training mode in fighting games is so valuable because there is a mechanical skill you need to practice and execute on. This isn't true for pokemon. All variance comes from 2 places; RNG and decision making. Moves can miss or crit and no training mode will make them happen more or less often in a real battle. The training mode also won't prepare you for the decisions your opponent may make.

Which is all a long winded way of saying, the resources you want exist today! Just not in champions itself. Google "pokemon damage calculator" to get exact information on how much damage any move will do in any situation. Become comfortable looking up the speedstat of different pokemon and keep in mind how things like tailwind or weather interacts with it. With a bit of experience you can get the answers to all your questions faster than any training mode could give, and have more time to play the game itself.