You can check your stETH balance on Etherscan by clicking the token in the dropdown menu. Rebases happen once per day at 12PM UTC. There is no transaction that takes place, as a way to prevent paying gas fees on a daily basis. Also, you can visit stake.lido.fi/rewards to track your daily staking rewards with Lido.
Where can I see my stETH rewards?
Your staking rewards are applied to your stETH balance.