First off, welcome to the forum and world of motorcycling.
Second, as others have stated, taking the MSF course first will give you an idea of what you're getting yourself into (around here, they use 250 Nighthawks). It is the same curriculum regardless of state (though the bike may be different)...so no worries there...and definitely worth the money.
As for your friend who doesn't think you weigh enough or have the upper body strength...ignore him. A very good DVD series, Ride Like a Pro, features women who weigh no more than you riding and even picking up dropped Harley Road Kings (7-800 lb bikes). On the bike, weight and strength won't mean much for street riding. When you drop the bike, its all about technique getting it back up.
For safety, I'm a big fan of getting versatile gear when you first start out. Textiles are generally cheaper, and many are 4-season (they'll feature zip in liners, plenty of venting, are waterproof, and, if you're interested in such things, available in a wide range of color options). Over the ankle boots and a decent set of gloves are also a must. For the helmet, the most important thing is fitment. Theres not a ton of difference in safety from one helmet to another...price differences are generally feature based (comfort, aerodynamics, venting, paint quality, weight, etc). Opinions vary wildly on gear...I prefer leather with armor and full face helmets...others will prefer textile gear or no gear...go with what you like.
However, the most important safety tool we have is our ability to avoid accidents...training, practice, and situational awareness are critical. The MSF course goes over that really well.
Anyway, there's a lot more involved, but I don't wanna write a novel