It is a 16 year old bike that sat. Problems are to be expected. I've learned that even for free, an old bike might not be worth it. Depends on whether you like riding over wrenching. I sit here pondering when to buy my $500 gas tank as who knows when the old one will let go. That is on top of multiple carbs, starters, brakes, many hours of labor, etc.
The good part is it runs and can be ridden. Idle might be as simple as turning a screw a 1/4 turn and new plugs. Or more likely a carb clean.