A correction on one of the English sentences:

Please check if the following translations are correct and correct any mistakes.

1) I don't go I'm not going to school today. - Сегодня я не иду в школу.
However, compare this with:

I don't go to school on Saturdays and Sundays. (По субботам и воскресеньям, я не хожу в школу.)

P.S. "I don't go to school today" is grammatically possible, but only if "today" is being used in the sense of "Egyptians don't worship Ra or Isis today"-- that is, with the meaning of "in the present era; at this general time in human history; at this stage of my life".

So you could, in theory, say "I don't go to school today (at this time in my life), because I've been serving in the military for the past five years, but after I leave the military I hope to continue my education at Harvard Law."

But if you mean "today" in the sense of "this 24-hour-period right now", then you need to use the present progressive tense: "I'm not going to school today (because I feel sick and have a fever, but I'll go to school tomorrow if I feel better)."

Hope that's clear!