In the search for a trainer (provided you keep the horse) specify that you need someone who is willing to teach you from the ground up. You shouldn't be in the saddle if you can't get some basic respect out of it. You're going to want to learn how to lunge and get the horse to respect your space by yielding its hind quarters, moving its shoulder away from you, backing up when you ask, and walking respectfully with you. If it doesn't do this already, or if you don't know how to do this already, you need a trainer that is willing to teach you and the horse. ASAP.
Riding and being around horses isn't JUST about time spent in the saddle, and technically, neither is being an experienced horse person. There is So. Much. More. to horses than being able to walk/trot/canter, especially as a horse owner. Basic first aid, spotting lameness, financials, knowing how to get ground respect and mounted respect, and being at least somewhat able to manage misbehavior are all keys in successful horse ownership. If you can't manage these things without another horse person guiding you, you are STILL a green rider, aka a newb, aka inexperienced. Honestly? I wish I had been able to call myself "experienced" after my first year of lessons. After two years I started riding greener horses, but I didn't have the faintest clue about ground control and only learned that the hard way (on the horse I SHOULD have bought.. after helping to break her in.)
You're still young and you're far from "experienced." If you're serious about this horse, seek lessons and a good, quality barn. If you're not serious or too frightened, sell it. It doesn't need to be in incapable hands and I don't say this to be mean.
But, understand something. You set your mind on finding a horse that was NOT dead broke and kid safe, as well as something that WOULD improve your riding/handling skills. That something fell in your lap, or otherwise there's good advice about being careful what you wish for. This is a good learning opportunity to take advantage of, even if it means getting a part time job and paying for lessons on your own.
-I haven't read the entire thread, but I'm sure this has all been mentioned before.