I'm naturally a skinny guy too, but you will gain weight if you get enough calories through fats like nuts, oils,eggs and meats and it will be good weight/muscle instead of water and fat filling your cells

You don't need carbs to gain weight, regardless you are still allowed to eat carbs through carb backloading after working out. Ideally after 7pm

Just make sure you Eat clean complex carbs that are gluten free and you will gain muscle and look shredded. You'll soon ask why you didn't try paleo sooner