Adjusting from 2-person to 3-person mechanics (2PO to 3PO)

[ilyazhito]

Is going to the blocks before each quarter random, or is it determined by where that umpire was when the quarter ended?

I don't know, because the intramural games I worked 3-person for used halves. Presumably, the umpires just go to the blocks on the same side they were for warm-ups before each half, and then to L or C, depending on where the throw-in goes for the 2nd half. (Placement for the 1st half and OT is predetermined, because those periods start with a jump ball)

Any other things that would confuse an official newer to 3PO?