You do need to see an attorney. They can give you the specifics about sealing or expunging. The age of the case doesn't matter. If you were adjudicated guilty you cannot get it sealed or expunged. If the adjudication was withheld, then you can get it sealed, but not expunged.
The rules concerning sealing and expungement can be found in the Florida Statutes, and the rules are very specific. For example, there are certain crimes that are not eligible for sealing or expungement. Also, a person cannot have ever been adjudicated guilty of any crime. In other words, only specific crimes for which you received a "withhold of adjudication" or charges that were dismissed may be eligible for sealing or expungement. You should contact an attorney to determine whether you are eligible for assistance.