It's perfect and needs no correction.

Thank you very much! But I am not sure that I understand why in the first sentence should I use that form of the verb "to come"?

Hi Yury, I've made some changes to your text below. You can use the community "notebook" board on italki to write English texts where people can easily make corrections to your text :). I hope the corrections below help! My name is Yury and I come from Saint-Petersburg in Russia – the biggest country in the world. I graduated from a Russian private high school in Saint-Petersburg “Peterburgskiy Standard”. Since graduating I have been living in China for 2 years, which has allowed me to gain knowledge about the culture of the country and the language. Restaurant businesses have always attracted me, and the faculty of Hospitality management (not sure what you mean by the faculty of Hospitality management? Are you studying there?) is an opportunity for me to obtain enough knowledge and experience about how Restaurant businesses work. In the future, I want to own a restaurant in the Netherlands or somewhere in Europe. Thus, I will be able to use all my creativity and the knowledge that I will have gained by the end of my studies in Wittenborg University.

You are right, Yury. That sentence would read better as 'I graduated from Petersburgski Standard, a private Russian high school in St Petersburg' (followed by the date of your graduation). If we use a past simple, we usually specify the time. Otherwise, you could say 'I am a graduate of Petersburgski Standard, a private Russian high school in St Petersburg.' That is the neatest way of saying this. There are various other corrections that are needed, mainly to do with tenses and article use. It would be best if you reposted this in the Notebook section.

Now, I am sure this text needs some corrections. Just found an error... I think it would be much better to write the sentence "I graduated high school from a Russian private school in Saint-Petersburg “Peterburgskiy Standard”." like this: I graduated FROM a Russian private school in Saint-Petersburg , which is called “Peterburgskiy Standard”. Because, I have just googled how to use this verb correctly, and most of the people on certain forums assert that saying "graduate high school" is incorrect. Is it so?