because your 400 speed is not super fast, make sure you are not going out too fast. since you top out at 68 in 400, you don't want to be going out too close to that speed.
because you are a distance runner you may already be running the race right, but if not:
many high school 800 runners go out too fast.
I would suggest something like this:
1st 200 - shoot for 34-35 when your are in 2:20 shape....for first race or so maybe best not to go out under 35....shoot for about 36 = 2:24 pace
2nd 200 - gradually settle in (most runners slow up some here so 37-38) has you coming thru 400 in 73-74
3rd 200 - because you are a distance runner you should not be slowing down much compared to other runners - so you might even be passing others in this 200 and holding 37-39
4th 200 - time to kick (everything you got left) by not going out fast you should be able to close faster than you start - 33
this gets you mid 2:25...if that works just try to take 1 second off per each 200 as the season progresses.
I have used 200 repeats with a lot of success for my runners. These are not fast sprint 200 but 200 with short rest to work on running quick when tired. possibly keeping the rest to as low as 30 seconds: something like this:
200 - 35-36 (30 sec rest) this first one should feel almost too easy since you are starting fresh, better to be slower than faster, so don't press the pace on this one.
200 - 35-36 (30 sec rest) or add 10-15 seconds if needed (so 40-45 seconds)
200 - 35-36 (30 sec rest) or if adding 10-15 - (take 50-60)
200 - 35-36
probably best to stop after 4 and then do a second set of 4 same as above. This is not meant to be a killer workout - the hard part is the recovery (with it being so short your breathing will still be labored = which trains your for the middle and later stages of the race so that is what you should be thinking about - holding your pace even when you are tired and breathing heavy. This also teaches you how to kick that last 200.
If my girls did 4 200's and then a second set of 4 200's under control, I would let them do 2-3 more a little faster with more rest (1 min) with spikes on for a little speed work. They might hit these in 32-33.