Build a base, upgrade leather equipment, weapons and a shield. Do not stay in the forest for a long time, go out on raids in search of food / ore / crypts. You can hunt trolls and make troll armor, it will be a good bonus to survivability. But strive for bronze armor and weapons, after which the dark forest will not become a problem. Also, make small houses in the forest with the ability to safely take a breath, cook food and get a rested buff, it saves a lot when everything does not go according to plan.