How to delegate XTZ and earn staking rewards?
You will see the details of XTZ on your wallet, click the position indicated by the red box in the image below:
Select the validator Wetez on the pop-up window by pasting Wetez's delegate address and click “Delegate”：
Check the amount and delegate address and click “Yes” to confirm all the delegation info:
Click “OK” to finish the delegation:
Press the "Update" button. After that, you will see the delegation in the window of your Tezos wallet, click the position indicated by the red box in the image below:
You will get the details of your delegation on the pop-up window: