Hello Oky. I'm also an English student. I can not tell you which level you are in, but I can make some corrections for you. Let's go!

You mixed two verb tenses: the present perfect continuous and the simple past. They have to be written separetly. You should say "I've been studying English since 2010." or "I studied English 8 years ago." Actually, first sentence is correct in this case because you're still learning English. If you use the simple past, it means that you studied in the past and stopped studying, because simple past tense is used for giving information about situations that started and ended in the past.

"Am I" is used for question sentences. The correct position in an affirmative sentence is subject pronoun + verb: I am.

"corrections" is not right in this case, because you're starting an imperative sentence, you're asking someone to help you. So you have to use a verb at the beginning of the sentence. You can use "could" to be more polite: "Could anyone correct my English?"

So, whole text would become like that:

I've been studying English since 2010, and using Italki since 2013. I don't know which level I am in. Please, correct my English. 

I hope this helps!