Trek is a good name in bikes and as others have suggested some comparable models it's worth the time to try them out as subtle differences make the difference between a bike that you love and will want to ride again and again and one that is ok feeling.

The bike shop and their after the sale helpfulness or lack of it will play a big role. If the shop is willing to talk to you on a level that you are comfortable with and not trying to dazzle you with bike lingo and their expertise you will have found a good shop. If they are truly interested in you and your experience on the bike you'll know by how they treat you and the questions they ask. If all they are interested in is unloading stock, you'll know that too by whether they are really listening to you or not.

People who are somewhat new to biking should be talked to differently and serviced differently than people who have been biking for years and a good shop will recognize that and adjust accordingly.

Welcome to the wonderful world of bicycles and congratulations to you for wanting to improve your health and fitness!