Is there ANY way that I can keep this off my criminal record? I'm a 4.0 student, involved in tons of extracurriculars, I volunteer in the community, I've never done anything like this before (clean record), and never plan to again. I would do 1000 hours of community service or whatever it takes. I just feel like if this goes on my record-even if I explain to potential future employers that it was just a stupid mistake (and just a single pencil)-it will severely impact the rest of my life.
We get the exact same sob story every time a shoplifter posts on one of these legal websites.

You get the Darwin Award and an entry in the Guiness Book of World Records for stealing something as cheap as a pencil.

The penalty for a Class C Misdemeanor is $1250.

https://www.oregonlaws.org/ors/161.635

You can get the conviction expunged from your criminal record after 3 years from the date of the judgment "as long as you have complied (completed all probation, community service, paid all your fines, etc.) with all terms of your sentence and have not been arrested within the last three years. You cannot have any criminal cases pending against you in any court. Also, you must have no other convictions, besides certain traffic violations, within the last ten years. You must not have had any other convictions set aside in the ten year period immediately preceding the filing of your motion. If you do not meet all of the applicable requirements your case may not be eligible to be expunged."

http://www.courts.oregon.gov/Marion/...ngementFAQ.pdf

If you get acquitted or get a dismissal you can file to have the record expunged immediately.

As for your trial, I strongly suggest you hire a criminal defense attorney. You've already said and done enough to guarantee a conviction unless a smart lawyer has some way of getting you out from under.