I guess you should first confidently win in offline mode on maps with high and "impossible" difficulty. But offline and online are completely different game styles. I've read a lot about players' tricks, and now I don't really want to play online. And there is still the problem of cheating... :(

That’s some nonsense… What does offline have to do with it? :)
And there isn't any problem with cheaters.

ces_137,
to play online, all you need is the desire to do so :).
And everything will work out. Forget about slang; you'll understand everything over time. Read FizMiG, and check out the links in my signature:

Rules – read them and reread them; most questions will disappear by themselves.

“Новичок” Tournament – in the first post of the topic, at the bottom, there are many useful links; go through them all.

/forum/section/62/
If you have time, read this section; you will find very much information.
There are replays, reports, and various discussions.
Be sure to read the reports, especially those that are detailed day by day.

If you have any questions, these people usually really help beginners, for which they deserve a lot of respect:

КостяN - ICQ 430-405-413
SEM_56 - 411-719-767
Wlk777 - 442-018-688
loi - 589-481-131
Lider1 - 469-887-869

I usually do too, but I'm swamped right now, sorry :)