You're going down in about a month? like the end of September?
For beach camping, September is hit or miss in my opinion. Some years the monsoon is still bringing rain in September so watch the forecast.
Usually, the mornings and evenings in September are really nice, but mid day can still get quite hot, so I would suggest lots of ice chests loaded with solid blocks just to make sure the food and drinks stay cold.
Fishing wise, La Pinta should be really good in late sept- especially in the evenings and when there is a rising tide. Throw silver and silver/blue Kastmasters (3/4 ounce or bigger) or chrome Krocodiles or other similar chrome spoons for spotted, shortfin or orangemouth Corvina and possibly some Sierra.
Smaller chrome spoons (1/2 or so) will also bring you some "less desirable" species like Leatherjacks or small pompano
Try plastic swimbaits, or 1/2 ounce curly tail grubs (in white or chartreuse) fished along the bottom in deeper channels and along the edges of sandbars for spotted bay bass, flounder,or California Corbina (not to be confused with Corvina mentioned above- they are different species, but equally tasty)
If the fish won't chase the artificials, then try fishing strips of squid on a Carolina rig (1/4 to 1/2 ounce sliding sinker about 12-16 inches above a size 2 or 4 bait hook) - a little squid on the curly tail grub mentioned above is also a good trick.
Good luck.
