Without knowing the type of business you run, the hours that you expect from your employee, the compensate package, whether there are any trade secrets, and a number of other matters specific to your business, it would be hard to give you an accurate answer. I would suggest that you sit down with an attorney for an initial consultation to tell the attorney the type of business, what type of employee you are hiring, your expectations, etc. Although there are general employment contracts that you can download from the Internet, there is not a "one size fits all" and every employee contract needs to be drafted at least specific to the needs of the employer. Best of luck.
Hire an attorney. It would take a few hours to discuss the matter and draft an appropriate offer letter and advise you on related agreements. You can then use these going forward.
This answer is for informational purposes only and is not legal advice regarding your question and does not establish an attorney-client relationship.