First off, has the nail hole been repaired? If not, fix that.
Does the boiler turn on? Are the pipes near it hot? How about after the circulator pumps? Zone valves? ALl fo the valves open?
Are there any bleed valves at the radiators or baseboards in the rooms that are not heating? Can you feel the pipes anywhere along the way to see if they are hot or at least warm?
Basics: the boiler must be working, the circulator must be pumping, any zone valve (if present) needs to be open (many have a manual by-pass in case their motor or controller is shot), and you can't have any air in the system (or at least much). Air migrates to the highest point, but depending on the pitch and layout of the piping, may accumulate lower somewhere. A circulator is rarely big enough to be able to push past an air block, so you have to make that path less restrictive by opening a valve to let it get flushed out. The system needs to have an air extraction system. Some are more effective than others, and they can corrode shut preventing them from working. You need to have the proper water pressure in the system or the safety circuits will prevent the boiler from running.
So, some more info would be needed to help diagnose the thing...