Congrats on your goals and welcome to the joy! So many choices out there...I would recommend looking at as many bikes as you can in the following categories:
road bikes (racing, recreational, comfort)
hybrid bikes (mountain bike wheelset, road bike wheelset)
mountain bikes (hardtail, full suspension)
comfort bikes
recumbent bikes (short wheel base, long wheel base, compact long wheel base)
recumbent trikes (tadpole, delta)
cyclocross/touring bikes
semi-recumbents

You can see there are a bunch! Some are better for pavement, some for off-road, some for a combination, some for long distance riding, some for tooling around the neighborhood. The more you get into it, the more you see that there are SO many styles meant for different uses. A good first choice is a hybrid as it might offer you more versatility...pavement, mild off-road.

But make a list of all your local shops and hit them all and check out the bikes...test ride them...as many as you can. See what you like. Make sure it fits, that it's fun to ride, that it's the color/look you want, that you can add accessories that you want, etc.

Browse the internet at manufacturer's websites to read some more details. It's a blast just trying to settle on one first bike. In time, you may come to realize that more than one bike is ok and necessary...i.e., mountain bike, road bike, whatever. I never thought I would, but since I've "gotten into it" in 2001, I now own: mountain bike, road bike, 2 recumbent bikes. I think my limit is 4, but it doesn't hurt to look!

Have fun!