B737 Captain reported encountering wake turbulence on initial approach to ORD in trail of a B787 and after landing; the flight crew turned onto the wrong taxiway.

Narrative

On arrival we were switched to 10C from our expected 9L; which switched us to southern right downwind. It also put us close in trail of a 787. In order to have proper separation; they descended us 1000 feet below them. It caused us to encounter wake turbulence. After exiting the runway and starting our taxi to the gate the Tower asked if our gate was available. The FO attempted to inquire with Ramp but the frequency was congested. While that was happening; we were instructed to hold short of SS. When the FO was finally able to get ahold of Ramp we were given confusing information about the availability of the gate. At the same time; Tower told us to cross at SS. As I tried to understand the information and comply with our clearance; I turned and crossed 10C at CC. We let Ground Control know we crossed at CC. We were given further taxi clearance and taxied to the gate without further incident.