Hi Mary, your sentence construction is very good!
There was only one error that I could find in your sentences. "Was" should be "were" in the first sentence as the tense you wrote I'm was incorrect, other than that, everything looks good to me! Well done!
Therefore, it should look like this:
"The vast majority of texts were written in Russian, and in this book we offer you their Georgian translations. Georgian texts that were published in various periodicals are presented here in English."