Welcome.

I would strongly suggest purchasing from a Local Bike Shop (LBS), unless you are very knowledgeable about bikes. If you order mail-order, unless you know what you are doing, the cost of having someone set up the bike and assemble will more than offset the savings from BD. Do you have a friend knowledgeable? or are you pretty handy??

If the sizing is incorrect you will hate the bike forever.

Anyway, enjoy, and my guess is you will be riding FAR more than 5 miles within a very short time. It happens to almost everyone who shows up here on the 50+ forum. I won't mention eating pie.

Good luck and let us know how you are doing adn your decision, which ever way you go.

(Sometimes LBS's have good used bikes and sales).