You can’t mine ADA on Cardano, I’m guessing you’re talking about being delegated to a pool (which doesn’t require a “rig”). Any good blockchain explorer can give you information about a wallet, see: Cardano Explorers – it’ll tell you which pool your wallet was delegated to. Though it won’t help you recover a wallet, you’ll still need to find your recovery seed phrase for the wallet if you haven’t got an instance of your wallet recovered in a wallet interface anywhere.