first of all, you need to enable Contract module. Home-Setup-Modules-Main modules-Contracts-Turn it on.
Then you have to create a contract on a Third parties tab, select third party and then when you click on a Customer tab, you will be able to create a contract.
Still, from my experience, it is only financial frame of the contract, not all the content of the contract.
I hope this will help. If you need any assistance, please get in touch.