First thing to do is to take a basic rider course. Then accumulate all the gear. Then think about what type of riding you want to do and read a ton of reviews and opinions.
Ride dirt bikes if you can. That's the best way to really learn how to handle a cycle.
NEVER buy a brand new cycle as your first. NEVER buy an extended warranty from a cycle shop if you buy from them.
A basic rider course will give you the basics of what you need to know to survive before hitting the street. There's no time for learning how to operate a cycle out on the road.
Depending on your budget, an older Ninja 250 is a good choice, as is a CBR250R and the Ninja 300. Any older used cycle you buy will need a good going-over, maintenance, and most likely new tires - so factor that into your budget along with gear. Used high quality gear is better than new low quality gear. FB or CL usually has good deals on good gear.
JKV hit the nail on the head. If you really want to get into riding and you know you do, that process he said atop his post is THE process to take to accumulate skill, safety, and fun as quickly as possible. I'm already into this, and I still want to get like a 125cc dirt bike just to put around the trails, and learn the ins and outs of traction.
Only thing I'd add to what JKV said is to find a trustworthy riding buddy to help teach you stuff. And not some dude down the street who almost dies weekly, lol.
I've been this person for a number of my riding buddies, and they got off to a great start. I was kinda on my own to start, so I took it slow and just went out every day to the canyons to learn to handle my bike, and self control. But many new riders I have helped get on their feet, they usually develop strange habits or other bad habits that only hinder their riding, or damage their bikes. Without someone there to say "yo what are you doing", sometimes you would never know before its set in stone.
That all said, don't go on group rides to learn anything. Im talking about one person, with bluetooth coms, who can help you get around town and watch your back.
And if sport bikes are your flavor of choice, (and even if they're not) I'd highly recommend a track day towards the end of your first season, with instructors. Sometimes you'll see bike crash videos online, where people just fixate and run off the road, and a track session would definitely help prevent you from doing that IMO. More control over your vehicle can't ever hurt.
Good luck, hope you find the corner of motorcycles that suits you best.