Welcome to TE to BOTH of you!!

Treks are great bikes. Take it a bit slow at first, and the fear of skinny tires will go away pretty quickly.
When you have time and inclination, learn how to clean and lube your bike. Then learn how to change/fix a flat. All good things to be able to do and gives you a sense of confidence. If you just bought your bike recently, the LBS (your bike store) should be willing and able to help you with such instructions.

Read this page for tips on safe biking in traffic:
http://bicyclesafe.com/

Most of all, enjoy riding your bikes!