You need to get the clutch engaged to find out whether the compressor is running.
1) Your clutch does not engage continuously or intermittently due to a problem detected by the a/c controller. It could be a wiring or connector corrosion issue (the car sat for a year). If this is the case, the chances are your compressor is fine (but you have a leak somewhere)
2) Your compressor seized up, and caused the thermal fuse inside the clutch coil assembly to prevent the drive belt from destroying itself. In this case you need a compressor plus dryer, and very likely condenser and expansion valve (due to crud from broken compressor). This would cost you north of $1,200, depending on the workshop. As you do not know where the leak is, and how bad it is, it may require other replacements too. If the evaporator is leaking, that would cost a lot of money, as the dash needs to be removed.
3) If you cannot test the clutch by applying 12V yourself, find a some reasonable technician who can do it for you, and tell you whether the compressor can be engaged. Once it can engage and running, you can check whether #7 is rising to 12 for example. If #7 is not going up much when the compressor is running, the chances are the compressor is bad.