Hi alegria and welcome to the forum
Make sure the tires are at least correctly inflated. Dealers are notorious for underinflating them to 28-32 psi. By your choice its safe to inflate to the maximum rated capacity of the tire 44psi. Many hyper milers push the envelope a bit and go to 50psi.
Don't be too disappointed if your MPG isn't great out of the box. It takes some time for the MPG gauge to "teach" you.

In addition to HalfNhaf's good advice one of the "tricks" is to find the _lightest_ pedal pressure (gas pedal) that will allow you to maintain the speed you choose. Commonly you will see the MPG gauge increase 5-10-15 MPG with lighter pressure and still be able to maintain speed (not uphill though

) FYI 72 MPHish is the maximum speed that lean burn will be available (Read: MPG will steeply fall off above that point).
Finally review the many techniques repeatedly outlined in posts scattered in the MPG forum.
Please keep us informed as your Insight ownership experience progresses
HTH!