I just took my 3 month old on his first beach trip where we stayed at my dad's private beach house. It was a 6 hour drive and he loved it! I packed everything you would need for him on a daily basis such as his ex-pen, his bed, toys, blanket, food (and bring extra just in case), food/water dishes, nutri-cal, harness and leash, shampoo (or a spray-in conditioner) just in case he gets SUPER dirty from running around the sand like mine did haha. Also make sure to have some bottled water on you for the trip in case he gets thirsty, but I'm sure you know all that
You should definitely bring your pup to the beach if you have the chance, he will have an absolute blast and you will too!! Have fun!!!