Use either the Daedalus, or Yoroi wallet to stake. Go to the delegation section of the wallet and browse the available stake pools.
You should search for our pool using the ticker ID “IMPI“. After you make your selection, please be patient as it will take the current Epoch plus the entire next Epoch for your delegation choice to go active on the blockchain. This literally means your delegation choices may not go “live” until the THIRD DAY following your selection.
Delegating your stake to a staking pool never requires you to send your ADA to a third party. Anyone asking you to send them your ADA so that they can “stake” it for you is attempting to scam you.
You are able to delegate your stake to legitimate stake pools without your ADA ever leaving your own wallet.