the first two things are generelly giberish but sometimes contain last minute changes to plans depending on the "defense"
as for the number of huts it's highly dependant on the situation, it's meant to cause the defensive line to slip up and go offside, so the words "Hike" won't be spoken generally because it gives the line an audio clue to move
When your in the scrimmage the QB will normally tell everyone what 'Hut' the ball will be shot at
I.E. Blah Blah Blah on 3, break
That way the offensive line has a change to get into their positions and have a bit of a jump on the defense given them that tiny bit of advantage they need to give the QB time to execute their plans. It's easier to to respond and act on the audio clues of the huts while the defense needs to watch for the first move or they can be fooled by said audio-clue and run offside
Hope that clears things up
(I Play Left-Tackle and have played football since I was young)