I am new to cooking. I have guests coming over. How do I know how much food to cook? I usually cook for 1 person and there will be 5 of us in total.
It can be difficult to estimate how much food you should cook, as the appetite of different people varies according to their age, body weight, physical activity, habits and genetics.

I suggest you follow a written recipe you like, with exact ingredient amounts for one person, and multiply the ingredient quantities by six times so you produce six portions. If one of your guests has a bit of an appetite they will be quite satisfied with the amount provided, and if not, you have one portion left over to enjoy the next day.

Do note, if you are new to cooking, that you take care not to undercook your meal, if you scale up your recipe. It is for example easy to overcrowd a pan when frying meats and vegetables.

Maybe I can help with scaling up the recipe you had in mind. What do you want to serve your guests?