Here are some general rules:
* Use a comma after "and" when it joins two independent clauses.
* Example: "The dog barked loudly, and the cat hissed in response."
* Don't use a comma after "and" when it joins two words or phrases.
* Example: "She ate a sandwich and a cookie."
* Use a comma after "and" if it's part of a series of three or more items.
* Example: "We went to the beach, the park, and the zoo."
Can you give me an example sentence so I can tell you if a comma is needed after "and"?