I had a wetsuit and when I was just in the sun (without going in water) it made me feel really hot lol. When I'm sunburnt I still wear my bikini I just load up on sunblock and wear an oversized t-shirt (my shoulders usually always burn). If you have a beach umbrella you should bring it, or just bring an extra towel to keep it over your legs if the sun gets too hot.
Wet suits are designed for wear in the water to preserve your body heat and such and so aren't really designed for all day wear sitting out under the hot sun. You'll get uncomfortable and sweaty in there after a while and I can't imagine you'll be having much fun. Instead opt for a a cute long sleeve sundress that can drape over your swimsuit underneath and cuter and much more light weight and breathable long sleeve tops designed for people like yourself who do tend to char in the sun. Also stay under that umbrella and slather... absolutely slather on that high powered sunscreen.