Hello I have brought a nc23 that has been streetfightered
I brought the bike.on the knowledge that its for the shorter person
Im 5ft8 and I can't touch the floor.with both feet :/ which makes me.think its been.raised up
How can I lower it and is it expensive

Im 5ft 0 and the NC23 is too tall for me. you being the extra 8" should be ok with it so yes it sounds like its been raised.
easiest way is to swap the dog bones & or the mono shock for the original ones.
can you post a photo of the mono shock? some on here will know to spot an original v CBR600 shock