My question involves a background check in the State of: PA

I made a stupid mistake and was cited for the summary offense of underage drinking in PA when I was 18 which got switched to a summary offense disorderly conduct so it would remain off my driving record. I am confused about how this will affect my career prospects as I hope to work for the federal government.

1) Will a summary offense of disorderly conduct show up on any background checks when applying for jobs, and especially for jobs with the federal government?

2) Being unfamilar with most formal job applications, will I have to state that I have been convicted of a crime, or are the questions normally just for misdeamenor or felony convictions?

3) Is there any way that this can get erased from my record?