As in 20's high cad 40 rest etc
2x20 - 2x 20 minute intervals, where you hold the maximum effort you can sustain for the duration of the 20 min interval - usually somewhere near to threshold. 10 mins rest then repeat.
10x1 - a series of 10 x 1 minute 'sprint' intervals, again where you hold the maximum effort you can sustain for 1 min (obviously likely to be a lot higher than the effort you can sustain for 20mins), 1 min rest in between. Might take a bit of trial and error at first, to peg the effort at the right level.
Tabata - A series of 10x 20 second 'flat out, no mercy' efforts, followed by 10 seconds rest in between.
Your HR max sounds wrong - especially if you were averaging today what you previously thought was your max. Presumably you recorded a higher figure today, use that as your new max. If by 'cad' you mean 'cadence' - then don't worry about it. Just use whatever cadence you need to use to maintain the effort - same as you probably did in the race today, without realising
All of the above not including warm up/down, obviously. Don't be put off by the race pace - there's nothing special about the fellas at the front - they've just trained harder, that's all. And that's all you need to do...