Decided on an Ending

Yesterday, I came to the end of my still-untitled diary novel. Or perhaps it should be called a short novel? There are 99 typed pages. It's a MG or YA book, so the length seems all right--what does anyone think?

I had been give a suggestion by a co-worker about how to possibly end the story after she and others had read what I had written up to that point. I had told them that what I had written then was only the beginning. Once she offered her suggestion, I got to thinking how to I could conclude the story--how the protagonist, Martin, really feels about having to wear braces.

As I have been saying, I have more ideas in mind for the protagonist that could easily make for another book. It seems to be thinking too far ahead, but now I might start thinking about these now, because I'm wondering what to write next. I also wonder if I need to do more work on the memoir before I send it to the publishing contest I want to enter. I only wonder how many people have entered so far or just how many are aware of the contest to begin with. And I have a dream written down that I may try writing from, even if it just ends being a short story. Though I know I will need to do some polishing of my recent work.