AirBnB is not going to help you find someone to co-host. What AirBnB will do is after you have identified someone that you would like to help you with hosting, AirBnB will allow them to set up an account and access everything in the host section of your AirBnB listings except for your financial information. So they'll be able to answer inquiries, approve guests, see your calendar to arrange arrivals, departures and cleaning. Co-hosts even have the ability to set prices.
If you would like someone to help you host, you'll need to recruit, screen and contract with them yourself. First, you'd have to decide what you want the co-host to do. If you want them to act as your surrogate so you never have to interact with guests or the unit, you probably will want a real estate agent who specializes in vacation rentals. If you just want someone to handle the physical aspects of hosting such as cleaning, meeting guests and maintenance, you might be able to use a housekeeper or handyman to do those things. But you'd still be responsible for setting prices, answering guest inquiries and approving requests.