Help me stock 13g

13 gallon, I got a 50 watt heater, a 100 gph filter, going to get 4 live plants, 2 pieces of driftwood, 15lbs of gravel. Large 23 inch bubble wall.

I think im going to stock -4 Platys -2 Dalmatian mollies.

Is that an OK amount? Also can I cycle the tank with 2 platy. Changing the water every 3 days?