Briar probably went to Alola for her honeymoon but if she went there on another occasion she would treat it like any other vacation: resting on one of those folding beach chairs, with an umbrella, sunglasses and a piña colada or another alcoholic beverage. Her Pokémon would actually enjoy the place tho (except Nickit because it's too hot and the sand is gross).

I think if her vacation extended long enough she would go shopping or explore some places because she has a lot of scientific curiosity. But mostly she would be on the beach.