Much and many have similar meanings, but different uses.

Much should be used when you're talking about a large amount, so many that you cannot count them or an unknown. It is most often found in negative phrases or questions, or questions concerning the cost of something.

   - Do you get to the beach much?
   - I don’t have much time.
   - There is too much traffic for me to wait.
   - I wish you much luck in the competition.
   - How much does the car cost?
   - How much time can you spare today?

Many is also used when you’re talking about a quantity of something, but usually a small enough amount that you’re able to count them. You’ll find many mostly in questions and positive phrases.

   - Our family plays many different board games.
   - There are too many choices of ice cream.
   - How many candies may I have?
   - Many cats were adopted this spring.