Hi Katya, it's very cool that you are intrested in nutrition and the science of Dietetics. I have been in the Health and wellness industry for 17years now. I have a number of nutrition certifications all focusing on slightly different aspects.
With so many school and certification options it's very helpful to know how you want to apply this field of study.
For me personally, my favorite program is Precision Nutrition programs.
I like PN because the knowledge gained is not only the book knowledge, but practical application too. Understanding the psychology of habit change is the most practical and useful knowledge I've ever received. Because, you can build the world's greatest nutritional program, but if the patient/client won't follow it, the nutrition knowledge is wasted.
If you have an idea of a field or profession that you want to apply the nutrition, I'll give you my opinion no problem.