what now

I have been to prison twice , the first time i was 20 i did 20 months, the second time for a stupid mistake that i dont think deserved to go to prison , i went for 6 months , on the second time i was 24 , i am now 29 and am about to finish college , im married with a family , i have a few questions , can i ever own a gun ? Can i ever clean my record so i can maybe teach ? I heard that after 10 yrs you can ask fr a pardon or some thing like that, is that true?
My offense were aggraved assualt on a police officer and the second time was evading arrest.
i want to be an instructor at my local college my major is cpmt -computer maintance technician , Is there any way to clean my record?

Sounds as if you have felony convictions and in most states that will limit your gun ownership at times forever.

You can see about an expunction as well, but it does not look great given what you have said here.