You need to consider size, cost, impact for the money, and what you want to lift. If you buy too little kite, and decide you really like it, then you'll be back spending more money again soon. Don't be intimidated by kites of more than 50 square feet.
Any large kite has a learning curve.
But all of them can be handled safely by one person once you get used to the process. But that doesn't really tell you anything. Actual pull depends on the size of the kite, the wind conditions, bridle tuning, and what drogues or laundry is attached to the kite or line. The best answers can be found in our line recommendations for each model. Whenever flying a foil of 30 or more square feet, we recommend good solid anchors.