As you may be aware both Oregon and California are part of the Drivers License Compact so if you plead guilty to the Oregon speeding ticket and pay the fine, the violation conviction will be reported to the California Department of Motor Vehicles.
If the violation is reported to California, the out of state points list does state it would be 1 point on your CA driver's license. From the information we have been able to gather, it does not appear that California would allow you to take a CA traffic school to clear this from your record since the offense took place out of state.
To see if you can take an Oregon traffic school, you will have to contact the county court of the area in which you received the ticket. Some counties in Oregon allow for traffic school for traffic violations while others do not. For example Douglas County does not use or offer traffic schools while Josephine County does.
In Josephine County, Oregon to be eligible for traffic school you must not have had any moving violations in the past 3 years in any state or attended traffic school within the past 3 years in any state. Also there cannot be an accident involved in the violation citation and the violation cannot have been written in a school zone, work zone or safety corridor.
In Josephine County, and likely other counties that allow traffic school, you must contact the court on or before the date listed on your citation, there will be a determination if you qualify or not for traffic school and if you do qualify a list of schools will be given to you. So contact the county court listed on your citation and see what your options might be regarding traffic school.