The most important thing is to clean up after yourself. You should leave the site as clean and pristine as you found it basically.
Also I didn't notice if that other family built that campfire from scratch or used an existing foundation. But if you can try and use an existing foundation when building a campfire and make sure to put it out when you leave. Building a fire from scratch out in nature can easily lead the fire spreading or picking up again after you're gone if you dont put it out well. Most forests with planned trails through them have spots at regular intervals where you can safely build a fire and cook food.
For the last page recipe, if it's to be classic Swedish food then it's probably Mushroom Soy (it's been around here somewhat longer and gotten more included in various pork dishes and stews) - but either should work.