With very few exceptions, there will be no copper in your water, unless you added it, or unless you corroded it off of a pool heater. So, to check for copper, check your chemical product labels. (NOTE: you are actually going to have to READ the fine print on the chemical ingredients, to check this.) If you haven't added anything that has copper in it, and don't have a heater, you probably don't have copper.
Iron is common is well water. If you have it, you probably already know that. If you have a softener, it will also remove the iron from the water . . . and you should fill your pool with that. Removing iron from an AG pool with a sand filter is not the easiest thing in the world. The sand filters are almost always 'over driven' (ie, the pump's way too big for the filter) and the precipitated (orange rust dust) is blown right on through the filter. Of course, if you do refill with softened water, you'll most likely need to be prepared to regenerate your softener several times.
But, green is not a common color from metals. If your filter is slimey and stinky, and has green slimey clumps, almost certainly, your problem is simply good old algae due to a lack of pool chemical maintenance.