You're constructing your if-statement wrong. The correct way to do it is
if(PlayerInfo[playerid][ADMINLevel] > 0 || IsPlayerAdmin(playerid))
{
/* Put your desired script here */
}
Your code was nearly correct (although it did have some unnecessary brackets), you just need to actually add a comparison to the ADMINLevel check. An if-statement should be like a question ("is admin level more than 0", rather than just "is admin level"). You can find more information about if-statements in Pawn here, and I think it will be useful for you to read.