Legal Question in Business Law in California

There are very, very few situations where a party to a contract may rescind (cancel) the contract within a specified time, or at any time. One example that comes to mind is contracts with door-to-door salesmen (Civil Code sections 1689.5-1689.15; other include endless-chain schemes, dating services, seminars, weight loss, and home-equity sales as defined in the Civil Code. Finally, other contracts can sometimes be rescinded on limited grounds, see Civil Code section 1689, including fraud, mistake, duress, etc., but proof of the existence of the conditions permitting rescission is not simple and someone seeking rescission on these grounds should obtain competent legal advice from an attorney who can read the contract and hear your explanation of the reasons before treating the contract as void or voidable.

You are not clear on what the contract is for so an attorney cannot tell you whether or not the contract can be rescinded unilaterally (cancelled).

There is no 'right' to cancel unless the contract says there is. That is unlikely. If you 'cancel' without agreement of all parties, you risk being sued. Choose wisely.