I have a weird question SOMEONE please answer me

Restless leg syndrome, possibly. I don't know much about it so I will just send you to the Wikipedia article: Restless legs syndrome - Wikipedia, the free encyclopedia
Lots of people have it to some degree.

Unless it is impacting your ability to live normally then I don't think it is anything to be particularly concerned about.

As for the erections, that's almost certainly just caused by the motion of your leg shaking. You could try wearing tighter or looser underwear and seeing if that helps to stop the vibration from moving into your groin.

 

Well the leg shaking thing is a common side-effect of stress and anxiety (go figure a closeted transwoman might be anxious!) and the arousal I'm going to guess is something to do with the various vibrations from that leg heading towards your mushy parts! I get that a lot, although I wouldn't go as far as to say it arouses me, so much is I just feel it in that area...

Doesn't seem particularly abnormal!

 

I shake my leg quite often too, especially when excited or nervous. I doubt there's anything wrong with you, and like Ridiculous said, the erections are definitely caused by your clothes.