Spd Pedals I Have A Pair Of Shimano SPD Pedals On And Old Mtn Bike And Need An Adapter For Them?

I have a pair of Shimano SPD pedals on and old mtn bike and need an adapter for them? - spd pedals

I have an old Specialized w / Shimano SPD pedals. Does anyone know where I am a series of adapters to allow me to Regual street shoes or sandals can go use that? Think of a platform, not allowing anyone slow ride for cyclists.

Thank you --