I want to teach you Russian :)

I want to teach you Russian! Can you help me and check my English text?

"Hi everybody!
My name is Sofia. I’m from Volgograd and I’m a native Russian speaker.
All my family is composed of teachers. ("is" is applied to "family" which is a collective noun but requires a singular verb. Think of it as the difference between family/families) My grandma and mom are the teachers of Russian language and literature. (Nice) And although I chose another (way/path) – I’m studying the medicine, but the teaching of Russian is probably in my genetic code. I will help you in studying of Russian with pleasure! (or "in the studying of" I can't really explain this one.) I believe language learning is possible only with native-speaker practice. (I don't think this sentence is completely incorrect but it would sound better as "I believe language learning is only possible by/through practicing with native speakers.") I’m studying English and know how it is difficult to orient in a foreign speech. (We might more commonly say "orient yourself in a foreign language/in foreign speech.") And how it is important to help a native-speaker. (Unless you meant, "And how it is important to get/receive help from a native speaker.")
I want you will be able to understand Russian and speak in Russian as freely as I do. We will talk about everything you want. I will help you with a grammar, pronunciation and understanding words. And perhaps you will get to know what is it a mysterious Russian soul.

Accidentally sent two.

They're both correct though "lots" is considered even more informal even though both are informal. People seem to argue over this considering that "a lot" can also mean a particular grouping of a thing, but I really think the distinction is almost nonexistent other than the subtle effect of "lots" sounding more childlike.

Usually "tell" is followed by an object. You could say, I couldn't find the right words to say. Or I couldn't find the right words. Or I couldn't find the words (though this might imply you had trouble speaking as opposed to having trouble finding the correct words)

The first one I can't tell a difference. The second one changes emphasis. "Only I went to the party" I'm the only person that went to the party. "I only went to the party." I didn't do anything other than go to the party, it's the only action I took. I was only trying to help them. (and nothing more) Only I was trying to help them (and nobody else tried to help) I was trying to only help them (and not do anything more than help) I was trying to help only them (and I did not try to help anyone else) I was trying to help them only (this one is unclear whether you're talking about only helping or helping only them, it might be clearer when spoken)

Interview

This year, I graduated from university, I majored in English, so I want be a teacher. I sent many of my resumes online. They will call me to interview. First, they will ask me to introduce myself, such as teaching experience or major. Then, how long will you stay this city? Do you have boyfried? When will you get married?(this sounds more natural)  They cover everything about you. Then they will say, "We will call you next week. How long will I keep this job? (I'm not sure what you meant here.)  They say, when the shortlist is finished, they will decide。

It was to be racist and threatening. The bananas were to insult the black woman and the nooses were a threat.

Depends on what your goal is but the short of it is to immerse yourself in the language and even try to spend time thinking in the language while you go about your day. Try to push yourself further and challenge yourself with tasks of increasing difficulty. Talk to natives. Be patient with yourself and try to have fun.