Hey Anais,
It looks like you have bus 672, about once an hour. If you google it you’ll find the schedule of buses that leave from Moncloa, and from Cerceda, but it won’t tell you the specific times. You should just be there at the time it leaves Cerceda, then check what time the bus really arrives to figure out how long it takes to get there. Then you can do the math.
Also, the typical Spanish thing to do is to ask the guy working in the bar next to the station, or some old man sitting around. They know.
Enjoy Mataelpino, I think I’ve just walked through there on the way to somewhere else. Have a nice weekend!
Daniel.