Now this COULD be an awkward one, but luckily it isn't too hard at all.
First of all, make sure to lower the difficult to very easy or easy to give yourself the best chance of getting this.
Next, practice, thats what its there for, take a few laps to adjust to the way the car handles, get used to the corners and where to brake etc.
Now, i did this in Australia, the lap times you should be doiing or aiming for are the 1:30s or low 1:31s. That should give you the fastest time in each session.
As for the race, if you lose places at the start, don't panic as the lower difficulty you set it on, you should have no worries catching up, and pass where a good place is available (Although you have the flashback ability if you do mess up)