Ok, just my opinion on the use of semi-colons (and the opinion of my teacher) is generally they don't get used these days. Instead it's better to end the sentence rather than prolong it.
On the use of commas, I know people that try and use them for extra emphasis. But you need to know when enough is enough.
With your first sentence, I'd put it as follows:
'Some films are educational, teaching us as students more about the history of wars, facts and historical dates.'
Hope it helps.
Student or Learner