Thanks, everyone for your advice! I did some searching around on Craigslist and ended up making a quick purchase. It's a Trek entry level mountain bike. The guy who I bought it from buys and resells bikes, and fixes them up. He did a good job tuning it up, in my opinion, and I walked away with my new commuter for $140. I got a new u-lock for $55, and will go back to the shop that sold me that for a clip on rear fender for another $25, and then set.
I attached a picture, but am not sure how well it will show.
Thanks again!
That will make a fine commuter, and you can save up and get the space horse for recreational pursuits where you don't need to leave the bike unattended. Because you are car free, you will still want a better cargo option. Maybe buy a trailer for grocery and big box runs.