glad you asked ... running a bad fuel mixture could ruin your engine. i have no idea what the correct mixture is for a ciao. my bianchi (minarelli engine) uses 2.8-3.0 oz of two-stroke oil per gallon. but someone here should be able to tell you the correct mixture (or your manual will).
you have to premix the fuel. buy some two-stroke (or two-cycle) oil. penzoil or valvoline are good (so is just about anything else). be sure it's not for marine use (water cooled engines). i've been using that w/o noticing for a while, so it might not be so bad. but i've heard it burns hotter.
i use a small container to measure out the right ammount of oil and pour that into a gas can. then go to the gas station and buy one gallon of gas. shake the can up a bit, then pour that into you gas tank. this way you always run a consistent mix and don't have to guesstimate how much fuel is in the tank ... and you don't have to shake your entire moped (which is much heavier than a one gallan can).
hope that all makes sense.