My toilet tank has orange a lot of orange stuff in the bottom. I tried flushing it over & over, but the orange stuff doesn't come out. What should I do?
That's most likely iron rust deposit, easiest thing is to ignore it; you aren't going to be drinking from the bowl anyway.
Otherwise turn off the feeding valve flush again to drain and start scraping.
Sediment including iron deposits can settle into the bottom of the toilet holding tank. This sounds like what is going on in your tank.
It is possible to flush out most of these deposits. Sometimes it might be necessary to take a brush to the inside of the tank to loosen up the deposits so that most of it can be flushed away.
Once cleaned up you may want to install a new toilet tank filler valve that has a tank circulation system feature. These have a tubing hose and a plastic piece with several jets that extend around the bottom perimeter of the toilet tank. Each time the toilet flushes these create an agitation of the water in the bottom of the tank and helps keep sediment from depositing in the bottom. I've installed these in my toilets and the tanks stay nice and clean inside.
Search for the name "HydroClean".
Empty the bowl by turning off the water supply, flushing, then plunging. Then use a pumice stick to clean away all traces of rust, scale, lime, and mineral deposits. The pumice stick will not scratch and works great.