Research research research! I read every thread on this damn site for months before actually taking off. Put together a good little pack. Met my first road dogs through here actually.
A good way to test the waters after getting your gear together is pretty simple; if you live in an area where it's possible, go camping on weekends! I really like public campgrounds that are a little remote, but have plenty of travelers, full time or not, coming through. You're generally more likely to find folks in that kind of environment are friendly and open to talking to their camping neighbors, and you'll make some cool connections. You can test your gear and survival skills, and your networking and socialization skills at the same time. Summer is coming up, and if you do it enough you're bound to meet some people to talk to about their experiences, maybe even someone to travel with. You don't have a car, so post on craigslist or local FB rideshare groups to get a ride out to the campground, or take city buses as far as you can and then hitch there and back. It'll give you a taste for what it's like without the commitment.
Example: When I hit the road with some folks I met on StP in 2010 we pretty much went straight to the hot springs in Oregon, and camped out near them. Met one of my best friends to this day there, who lived in the area and housed up travelers she met at the springs all the time, and she ended up hooking me up with all sorts of knowledge and connections.