I don't knock anyone who enjoys outlining and who finds this approach works for them. If the idea of outlining sounds appealing to you, do it.
But, if, like me, it makes you want to puke, or never write again, then don't.
You must, however, know what your character's main goal/problem is. You don't have to know it in the first chapter. I sometimes write a couple of chapters or chunks of story to feel out my MC, and then figure out what he's trying to do.
So, my MCs tend to want to achieve some impossible goal. Asking themselves, "How on Earth am I going to do that?" they pursue it with an intensity bordering on panic that they might fail.
Meanwhile I write, asking myself, "How on Earth am I going to get my MC to do that?" I pursue it with an intensity bordering on panic that I might fail.
Yes, it's nerve-wracking. It's also great fun to feel like I have as much at stake as my MC, to be as surprised as he is at when and how it all works out.
If you're just stuck, and you've been spending too much time writing, try some real life for a while. If you haven't really been working much, then follow some of the suggestions above. If you're still stuck, brainstorm about a new project. I always have more than one going at a time, and almost all of them get finished.
As Maestro said, never delete writing you're unhappy with. I have files and files of cut scenes, false starts, story ideas that have yet to be written, etc. Just like the stupid mistakes I've made in my life in general, which end up surprising me with fruitful results years later, your writing mistakes can yield you stories you can't imagine right now.