Beth-good for you for jumping in and asking questions! I wished I had signed on here early in my course days, as I almost gave up writing due to a inner conflict. But, with encouragement from my instructor, and my tenacity, I decided not to let those days upset me. Oh, I still get those blank pages staring at me. However, I do other things to get inspiration.
Don't scrap any of your writing ideas. Instead, get a seperate notebook/binder, and keep those ideas in there. Even if you decide to write something else, later on, you may need some inspiration for a different story. This is where your idea notebook comes in handy. Or, maybe you're missing just one scene. One of those ideas may fit into what you're writing.
It's okay to change your story entirely. If you're not comfortable with the story, put it away in that notebook. Then you have several choices:
1) Go to a library and thumb through the kids section. Read books that look interesting to you. Or, ask the librarian for what's popular these days. Again, read them. Reading is part of writing! I love the excuse to be able to go through the books that the kids are reading. They seem so enthused by picking up a book from the library. I want to know why they want to read that book!
2) Go back to your story after two days. You may look at it and decide that it isn't that bad of a story and that you just need to tweek it. Or, you may stick with your original thought that it just isn't working. That's okay. Writers don't use paintbrushes to put the picture/story on paper. Nothing to erase or throw away, (and no stinking turpentine! LOL). Looking at a blank page can seem daunting. I look at it as a challenge. It's just a piece of paper; it's not going to kick my butt!

Do you have kids of your own, or know of someone with young kids? If you do, great. Get their feedback on what kind of books they like to read and ask why? Is it the story or the character they connect with? Etc.

There's no law that says you can't start over!! You're not a failure. You're not letting yourself down or anyone else. I went to a conference 2 months ago. The best advice I heard was, 'Yes, there are guidelines put out by editors and publishers. However, if you don't write for yourself, then you're not truly writing.' Besides, editors and publishers want unique. Think quality, not quantity!
4) Even established writer's have been turned down....numerous times. I haven't sent in any submissions yet, therefore, I can't speak for myself. I'm still trying to perfect my writing. But, I do know of those who have been published and they still get rejection letters. Or, there are those who I know are good writers, but they're getting rejected. You're in one of the toughest markets out there. But, that doesn't mean we give up. Instead, we keep working at it, getting rejection after rejection, until someone appreciates our writing.
5) Relax! You're not alone. We've all had to start somewhere. I was told by my instructor to write on note cards, 'I Am a Writer,' then place them where I'd see them several times a day, like on the bathroom mirror, or in my car, near the phone, on the computer, etc. And tell yourself that during the course of the day. I left my job last year to begin following my dream of being a writer. I've had wonderful support from my family. When I go out into public and talk to people, I'm asked what I do. I tell them, "I'm a writer." Even though I'm not published, I've received nothing but praise for doing what I do! Yes, I've had one negative response. But then again, that's what toughens writer's up. I'm not out to prove to the nay-sayers whether I can or can't do this. Just me.
Keep up the good work. Keep asking those questions. Just wanted you to know, we're all in this together. Chin up! You'll be fine!
Kim
PS-I'm with Deb on the critique group. I've met some wonderful people who've given me invaluable support, both writing and personal!