Hey there! In the first room you spawn is a bookshelf with all the recipes and controls in the game.
Basically, you have to put stuff with water in the cauldron to make a healing potion. This can be picked up with an Erlenmeyer flask in order to use it in the game. You have one flask at the beginning, the others have to be crafted. Please note the recipe for an Erlenmeyer flask is 1 log and 1 iron at the oven, not 1 sand.
Thank you for playing anyway and if you have further question, feel free to ask :)