Theres not a set rpm that you should shift at. It depends how fast you want to accelerate. Anywhere between 2000 and the redline will do fine!
Stupid question BTW
i think you should shut up and keep making up ur fake lil stories, dont come her and start to say shit about this question, on a better note, just shift wen you need 2 like if you wanna drive slow then shift at the rpm the manual said but if you wanna go faster then rev harder its totally up to u