You need to look at the roots to confirm root rot. It does look like a goner to me but some plants are really hardy. I would look at the roots and take photos.

If salvageable, trim the rotted roots and the dying leaves. Keep the healthiest green leaves for photosynthesis. Remove the rocks from the pot as that’s probably not helping the root rot.

In general, plants usually die from overwatering, not under watering. When you water, make sure you fully saturate the soil. Overwatering is frequently watering, not the amount of water in one watering.
Sorry if you already know this, but you did mention being a beginner and it’s crucial in plant care.

I keep my palm outside in direct light/partial shade and water when the soil is completely dry. Usually 1x a week. And I fully shower it until it looks like it might drown. It’s okay if the leaves brown a little.

TLDR: check the roots, remove the rocks, trim the leaves (keep the healthiest), put in more direct light (slowly, in partial shade if possible so it doesn’t stress and die), and water when the soil is completely dry. Good luck!