New Player Questions

[Cthulhu Girl]

Hi, I recently started playing and have enjoyed the game so far. I have a few questions though if anyone has a moment to help me out:

1) When I first entered the world a help menu popped up that taught me all about the game, particularly the mutations and what they did. How do I bring that up again?

2) How do I gain health back?

3) What determines if a mushroom is consumed immediately or picked up when you interact with it? It seems like half of them I can pick up and save for crafting but the other half get consumed immediately so I can't use them to craft the soups.

4) Any tips on how to kill the purple panther things around the water area? My noobish attempts are not going well :)