Take a deep breath and relax. You are only being asked for your employment history not what you doing on a friday night five years ago ! If you have a period when you were travelling around or simply unemployed than say so. Disclosure Scotland
are only carrying out a basic check of any 'criminal' convictions so
provided you only have a for example a couple of speeding tickets then no problem. When you do submit your application be aware that it could take upwards of two months to come back due to backlog.
Goodluck with the job