With your limited knowledge of how the starting circuit works and no assistant, this is going to be a tough nut to crack on your own. I'll try my best to explain what to do, but I'm not very confidant we can get it done. First, you have a three post starter mounted solenoid. Large post, red wire, is positive from battery. Large post, braided wire, transfer wire from solenoid to starter. Small spade post, blue wire, solenoid power wire coming from key switch. You should have a small red wire coming either from the battery post on the solenoid or the positive post on the battery, going to the key switch. This wire powers your system and most times has a fuse inline somewhere. You've never said if you found or checked the fuse. You also did not follow the procedure directions to the letter, which makes it difficult to interpret your answers. Remember we are not standing beside you and your must paint us a very clear picture of what is happening. Also, during this procedure you will only use the volts setting on your meter. Please, repeat the procedure, with no assuming we know or your think anything is good without checking or testing.
I shouldn't say this, but from what you have told us so far, I think you have two problems, which will make this problem even harder to solve. First, with this system, you should not be able to start the engine by jumping accross the two large terminals on the solenoid. If it does start and run this way, your starter bendix is stuck in gear and can cause major damage to your unit if run this way. Second, it does not sound like you have any power to or from the key switch. This is why you have no power on the blue wire or to the clutch.
Don't doubt your ability to solve this problem. You can read and are willing to try, makes a big difference, just slow down and DON'T ASSUME ANYTHING. An assistant would also be a big help, as you only have two hands and short leads on your meter. I've been doing this for way too many years and more than once it will take me more than a day to solve these type of problems. Good luck and let us know if you have more questions. If you do report back, please include the tractor model and serial numbers located under the seat, so we can fid a wiring diagram for your unit.