Im running a 800m race how do i keep up at a steady speed?

right before race:

warm-up and stretch really good
have good healthy carbs and some proteins the night before
get 9 hours of sleep, get to bed early
drinking a gatorade 1.5 hours before, for energy
eating a big breakfast that morning

during race:

make sure you breathe really well! reallyyy deep, rapid breaths! start breathing well way before the race even starts, also. start it like a couple minutes before, when hes getting you ready. and then breathe well the whole way. focus on your form and breathing, and think "machine, machine, this is easy, i have to beat everybody" and just don't let yourself fall behind no matter what.

AND ALSO, PACE YOURSELF. start out at a speed you KNOW you could do 2 laps at constantly, and then after the first lap pick it up a little bit, then burn on the last 200. but remember; dont start out TOO slow! if youre falling way behind on ur first lap, pick it up a little bit. try to be with everyone else, mainly; they'll be doing the same thing.

outside of the race:

eat healthy every day
get good sleep every day
do some lifting and plyometrics outside of practice
WORK YOUR A*SS OF DURING PRACTICE!
practice running at just about race speed every single race, and ESPECIALLY the last race of each practice day!!!

A good warm up (10-15 minute easy jog), about an hour before you race is where it starts. After that stretch out really well. Do a few hard strides before the race starts to get the juices flowing.

When the race starts get out hard the first 100m, but don't lead unless you are much better than the others in the race. Tuck in the first lap with the rest of the field, but don't let yourself get boxed in. The key is to not go out too fast at the start of the race. If you can keep the first lap in control so that you have enough left in the tank to survive the next lap. Stay relaxed through the next turn. I start to open my stride around 250-275m to go. 200 to go, I start finding my higher gears and start to accelerate. 150 left but everything you have left out, leave it all on the track.

Really run based on how you feel, but try to be on the conservative side. I have seen many people run what they thought to be a controlled first lap, only to fall apart on the back stretch of the second lap.

When you are finished get a good long cool down in. 20 plus minutes. Your legs will thank you later for it for flushing out all the lactic acid and you will be ready for your next race.

on a track?
if yeah..
you want your first few steps on that turn to be quick,
relax on the first lap then gradually speed up,
run the curves at a faster pace than the straights,
last 100m should be a full out sprint

don't run too fast or slow

what i usually do is keep a pretty fast, steady pace for the first lap. on the last lap u should run pretty hard at the beginning and sprint at the end. thats what i do. hope it helps!!