Trying to take a scenic flight with the A5 at 500ft. But even when i set the altitude that low in the flight plan, the AI won’t go below 2000 ft while flying. 
 

im a novice at this stuff so i apologize if i get the terminology wrong but I think it’s because i don’t have IFR clearance for under 2000 ft. Whenever i ask to set my cruise altitude there it’s denied. Is there any way to override the AI ATC?

You wouldn't be filing IFR at 500ft as it's below any usable IFR altitudes. If you want 500 or lower, then just go VFR.