Women's Attire Recommendations:

Elevated maxi dress is a good option along with satin silk or other material high-low and midi dresses or a classy jumpsuit or pantsuit. Opt for bright colors, pastels or formal metallic, as well as simple patterns. As for accessories, look for block heels or a dressy wedge. Elegant jewelry is a great way to add an extra dose of formality. Since the wedding will be in a grass field, you may want to skip the stilettos.

Men's Attire Recommendations:

a suit is your safest bet, but skip black and choose a color like blue or tan instead. Summer fabrics, like linen and seersucker, are appropriate for this dress code. Tie or bow tie, belt and complementary dress shoes preferred. No shorts please and thank you

https://www.theknot.com/content/what-to-wear-to-a-beach-wedding