+1 Don’t worry about others.
Ride your own ride.
I went into the MSF course last fall never having ridden a motorcycle either. The first day was challenging learning the muscle memory for shifting, clutch, and brakes. Riding was very easy at decent speeds, it was slow speed maneuvers, stopping and changing gears that required habits I did not yet have. By the second day it just started coming to me and things started happening with out near as much thought required.
The course is designed with new riders in mind, so there was no expectation that you have those skills.
As for a first motorcycle. Find one you feel comfortable on and don’t worry about the style, sound or what others think. You will be having too much fun. I would suggest waiting until you have taken the course so you have a better idea what you may like and don’t like. And I would look at a used bike. A late model used bike is usually much cheaper than a new bike and if you take care of it, it will lose little value. In addition because you have less invested you will be less worried about minor damage from a slow speed drop.
There are a number of good choices out there for a first bike. Don’t feel you have to start on a small “cruiser” just because you want to get a Harley at some point. The standard riding position may make it easier to learn to ride. The TU250x is a nice retro standard that may appeal visually. The Ninja 250r is a faired bike with a standard riding position and is one of the most capable small bikes on the highway. Dual sports and supermotos are very light and more damage resistant than other road bikes and give you the option to ride more places.