You definitely have to agree upfront on what stake/salary your employee would get. And when you say "this is my vision and things should be done my way" it makes me think you're looking for more of an employee than a cofounder. Which is fine, by the way, just be aware that that isn't a very cofounder-like mentality.

You're still very early stage, so the first person you brought on would probably need a significant chunk of equity, unless you're paying a nice salary.