To clean the tank from the worms I would use a very diluted bleach solution. Throw away filter media and make sure to rinse well. Like, really well. Then dry everything and rinse again
Breeding mollies isnt a good hobby for a 30g tank. Only 10 can fit in at most without overstocking the tank, and since they are livebearers they can have lots of fry and very rapidly.
Instead of breeding maybe just have a community tank. They are very rewarding and very easy if you get the right fish.
What other fish and how many of them do you have? What size tank are you going to put them in? This will help greatly on what you can do with them.