Mae,
I don't think your question is silly at all, though I'm not the best for suggestions. I have lived in this area all my life, but the beach was not something our family did. I have a 6 yr & 8 yr old son I'm still trying to get to the beach for their first time!!!
Cape May is an expensive area. I'm not sure exactly where you live, but I have a friend who has taken her 2 girls since they were very little to Pt. Pleasant Beach. She said it's nice for the kids as it has a boardwalk and doesn't have a long walk to the water from teh boardwalk. She said that it is very clean there.
I have only been to the beach myself a few times, but I would bring towels or blankets for on the beach or chairs from home. If you're taking a camera, be sure to bring a bag to keep it in when not taking pictures so the sand doesn't get in it & ruin it as the sand will get EVERYWHERE.
I would also suggest bringing towels to keep in the car to wipe your feet, etc. off before you get back into the car.
Other than comfortable shoes for walking in the sand (water shoes are great for that as you can walk down by the waters edge as the little waves come in for you to take your son into & let him get his feet wet).
Other than that, I'm not of much help.
Good luck & have a wonderful time.
B.