After 10 years the gasoline has probably gummed up the carburetor. You could try fresh gas and oil and see what happens but you'll likely need to disassemble the carburetor and clean it.

I am not sure from your description exactly how long it was stored with gas in it. If it's really been ten years, mike's advice is spot on. If it's only been one season or so, I would try starting it first. If it starts at all, even if it runs poorly at first, you can always dump out the old gas and fill with fresh. But if that doesn't get it running, the carb is gummed up and will have to be opened up. You'd want to take it to a shop for that.