Yamaha TTR125 LES won't start! Help!

Hi everyone! I have a question concerning my 2004 Yamaha TTR125 LES. It won't start! :( It sounds like it wants to, but it's not kicking over. Any ideas on what it can be?

Also, is this a 4-stroke or a 2-stroke? I think it's a 4, but wanted to make sure. ;)

I'd appreciate any ideas/help I can get! Thanks in advance! :)

I've been searching around the net in hopes of finding a great discussion board about dirtbikes where I can find help from people who know what they are talking about. hehe I'm glad I found this board! Awaiting your replies. :)

P.S. Sorry for my ignorance on my 2 questions, but I'm a girl and I just got the bike. Don't know anything when it comes to troubleshooting, repair, etc.

Thanks for your reply! :)

Well, I did buy a spark plug, so that will need to be put in to check. However, I thought of something else:

For a 4-stroke your suppose to use straight gas (right?). Now, what if something happened in which mixed gas was put in there? Yikes...could this result in permanent damage? Is the bike permantely screwed? :( I have a feeling that's what may have happened. Sorry about all these q's, but I just thought about that and I worry that's why it's not starting. ??