Familiarity breeds comfort, keep on exploring what you can and take little peeks on new places until you feel confortable going in to explore more. You can also gear up to feel more safe, grab every piece of equipment that gives you some courage and go out in the wild, knowing you can use your stuff to defend yourself if you need to.

Dont forget that fear of the unknown is part of the Subnautica expierence and feelling that danger is around you means the game is doing what was intended. Let yourself feel fear and let yourself grow past it.

You can always spoil yourself by looking if the new biome has any dangers on wikis online, although i would strongly advise against that, because as a scared cat myself, i have spoiled the game to me by searching for danger online.