A couple basic tidal questions

Just installed Tidal . Searched around for what i thought would be questions i could easily get answers from google . No such luck . 
First question - where to set volume slider ?
Second question - Under settings (sound output) should i use system default or built in output or my dac shows up Ayre qb9 
Use your DAC, with volume on the Tidal slider at max.
Your amp controls the volume, not Tidal. Tidal has no volume control or equalizer. 
Your computer should route all sound to the driver for the Ayre, and when you install the Ayre driver, this should normally happen automatically (at least it does with Chord drivers). This becomes the system default, so Tidl can simply use the system default. And your computer volume should always be at 100%. Use the amp volume control exclusively for best results.