I don't play football myself, but I have often see relatively organized amateurs (I mean, teams with same color tricot) train and play in the field opposite from the main stadium in the 700y complex. If you don't know, ask for the track-and-field or petanque, it's at the top of a small road leading up from the main circle road. Perhaps you could ask there.
However, the whole facility was being refurbished during Covid, I am not sure it's re-opened by now