For advice on first two miler I say, break it into fourths as you would a mile or 1600 meter on the track.
First half mile, don't go out too fast, establish position.
Second half mile, get into a rhythm and cruise by the 15 year olds who went out too fast. Don't fight them if they surge, they won't last.
after passing the one mile marker, fight the natural tendency to slow down. Depending on the race, you can pick off a lot of people here. If you arent catching the runner in front of you in this segment, you are probably slowing down.
The last half mile, grit your teeth and fight for your position. The pecking order is 90% complete now, only finishing kicks will resort the final ranks. Get a mental boost from the fact that you are nearly done and everyone else is hurting just as bad (or worse) as you.
Don't start your final all out kick any sooner than you would for the mile or you will rigg up in the last 75 meters.
If you are in the 4:30s for your mile PR, you've got a good chance. I would say 4:48 would be the slowest mile shape you could be in to realistically shoot for sub 10 in the two mile.