Cardano staking with Yoroi mobile wallet

I see the Cardano balance in the wallet on Yotuube is very large, around 991 Cardan, if Cardano costs around 2 USD then the balance is around 2000 USD and that is really big for me who doesn't understand how the Cardano coin works.
I also feel that this Cardano Coin is very worthy to be kept, don't let us sell it because the value of Cardano is very good because it slowly increases and provides passive income benefits from staking delegates at Yoroi Wallet.