Yogurt:
Dairy option: instead of yogurt you could use buttermilk, cottage cheese, and ricotta cheese.
Dairy-free option: instead of yogurt you could use plant-based yogurt such as soy yogurt, almond yogurt, oat yogurt, coconut yogurt.
Cheese:
As a dairy-free option, you can go with nutritional yeast (if it's available in your region). Nutritional yeast can be a good substitute for cheese because it's rich in protein and B-vitamins while being low in fat and sodium. It's yellow in color and is available in both powdered and flaked form.
Parmesan cheese - instead of it, you can choose Gouda cheese, cheddar cheese, mozzarella cheese.
Blue Cheese - instead of it, you can choose feta cheese, Gouda cheese, cheddar cheese, mozzarella cheese, parmesan cheese.
Feta cheese - instead of it, you can choose Gouda cheese, cheddar cheese, mozzarella cheese, parmesan cheese.
Gouda cheese - instead of it, you can choose cheddar cheese, mozzarella cheese, parmesan cheese.
Cheddar cheese - instead of it, you can choose Gouda cheese, mozzarella cheese, parmesan cheese.
Cottage cheese - feel free to substitute it with ricotta cheese, yogurt, or low-fat cream cheese, mascarpone, mashed silken tofu.
Cream cheese - feel free to substitute it with ricotta cheese, cottage cheese, yogurt, mascarpone, mashed silken tofu.
Milk - feel free to use yogurt or plant-based milk such as almond milk, soy milk, oat milk, rice milk.
Eggs:
Mashed Banana (1/2 banana per egg).
Silken Tofu (to replace one egg in a recipe, purée 1/4 cup of soft tofu).
Ground Flaxseed or Chia seeds mixed with water (for example 1 Tbsp chia seeds + 2.5 Tbsp water = a chia egg)
Yogurt (dairy-free or regular) - replace 1 egg with 1/4 cup yogurt.