The best way to read Tokyo Ghoul manga in order is to begin with the very first issue. Make sure to follow the volume and chapter numbering. Sometimes, there are guides available online or on manga forums that can help you figure out the exact sequence if you're confused.
Well, to read Tokyo Ghoul manga well, first, familiarize yourself with the characters and the basic plot. Then, take your time to enjoy the detailed art and the story's progression. Also, try to understand the underlying themes and messages the manga conveys.
Tokyo Ghoul manga is quite lengthy. It has a lot of content to explore. The specific length depends on how you count the chapters and volumes. But it's enough to keep you engaged for a while.
It's hard to give an exact number. Different editions and compilations could make it tricky to determine. You could check with manga collectors or search on authoritative manga websites for a precise count.