Follow your gut instinct. It sounds like you're a roadie at heart. You don't need to ride that bent over. You can set up the bike so you're more upright. Drop bars are great for giving you lots of hand position options.

You may want to take a bike safety course if there's one offered near you. You'll also need to learn some basic maintenance, like how to change a flat. If you have a great group of family and friends who will not mind coming to get you if you have a mechanical incident, you can get away with just carrying your cell phone at first. Eventually, the day will come when you're stuck and you can't reach anyone, or they're unable to drop everything and come get you, and you'll start carrying tubes, tools, and some method of getting air or gas into your tires. Even still I sometimes get stuck. I have a taxi # in my phone for real emergencies, but I haven't used it yet.

You should try to test ride as many bikes as you can. I admit, I did not follow that advice, and it worked out fine. I bought a used bike and it was good for my first year, then I upgraded.

Most important, have fun, and ride!