Wow, I have only ever flown with a pet in the cabin with me, so I have no advice for flying a puppy as cargo.
As far as the beach goes - the first thing I would be concerned about if dogs are allowed on the beach? I have been to a doggy beach before. There you must be prepared for all kinds of dogs - big and small. Definitely take plastic bags to pick up anything you wouldn't want on a beach
- a towel for your pup, definitely some shade - like an umbrella, a bowl and some water. perhaps doggles, and if she likes to chase things, a ball.
Be prepared to rinse her off in the shower area when you're done, as you will have a sandy matted mess, then head home for the official bath, so bring all your regular doggy supplies.
I wonder how hot it will be where you're visiting, that would be my other concern. Please take into consideration, how hot it is and how long you keep your furbaby at the beach