Gold Colored Metal Table (what kind?) with Rust

I found a gold tone table that's all metal. It looks like one of those elevator panels, sanded in a circular pattern - but it's gold. Now it's got rusty spots too. I'm in 9th grade & want to figure out what kind of metal; and how to remove the rust. Could it be brass polished that way? I don't want to sand and ruin it, or paint over the cool effect.

The bottom shelf is fine, it's just the top shelf that is rusty. How can I tell how to solve the problem?

First determine if the object is plated steel or a copper alloy (copper, brass, etc.). This can be done by using a magnet. Steel as a base would be magnetic, alloys of copper would not be. If it is indeed plated, removing the rust would just leave unfinished steel behind.
If the table is a copper alloy what you may have is not rust but an oxidized area where a protective finish i.e. lacquer may have come off. In this case you can use a tarnish remover/polish then recoat the table. If it becomes necessary to remove lacquer from the table top, do the polishing after then recoat a clean surface.