I think the easiest beginner's recipe would be 1 cup spinach, 1/2 cup blueberries, 1/2 cup strawberries 1 banana, 1 Tbsp hemp or chia seeds, 1 1/2 cups coconut water (or almond milk or regular filtered water). Add in some vanilla protein powder for more of a meal replacement.
I also like the combination of spinach, pineapple, mango, chia seeds, banana, and coconut water!
Over time add in more veggies in place of some of the fruit. Avocado makes it nice and creamy (1/8-1/4 avocado is a good amount) and adds in some healthy fats.