Is there any example of a solidity smart contract with staking and taxes for the development wallet?
Thank you in advance
Hi, welcome to the community! 
Not sure which features you want to implement.
Well what most projects are meaning with staking is that you put your tokens into a contract and then you get more over time.
For this you need a mapping to know how much was deposited.
You need rate (per day, week, month, year whatever you like to choose).
Whenever someone deposits or withdraws you can add the reward that he got til now to his unclaimed rewards.
If you like someone to develop a staking contract for you, you can contact me on telegram: @solidityX