It might be simplest for you to simply re-install the UR22 (or perhaps a de-installation followed by a re-installation).
I would check to see if any Steinberg courses are being offered in your area, live instruction is often better.
There are a number of video tutorials available on YouTube - many from Steinberg itself. There are is also a Certified Tutorial available in the Steinberg Shop which I can readily recommend : http://www.steinberg.net/en/products/accessories/steinberg_certified_video_tutorials/swa_complete_cubase_7.html
I’m sure a few people will respond with recommendations for books and other printed guides.
I think it would be advantageous though if you would, in a few words explain or describe why you want to use Cubase? What are your goals or aspirations?