Hawaii vs St Lucia??

We’re getting married end of August!!

Neither of us have traveled much, not even sure where to start exactly.

We want a combo of beach/pool relaxing, some excursions (kayaking, zip lines, caves/hikes) and LOVE animals.

I’ve only been to Hawaii as a pre-teen. Neither of us have been to St. Lucia.

Budget TBD but we’d like to save as much as possible/get the most bang for our buck.

Flying out of DTW.

Would love to go this year but willing to wait for conditions such as better weather.

Any suggestions? Pros/Cons? Must sees/absolutely skip?

Plz & thx!!! (Also open to other suggestions)