Fill my Fox Shock with Air
The blue thing is a 3 position lever, which controls how fast the air moves between the two chambers.  Looking at it directly, 


LEFTmost position  is FIRM, ie pointing at your drive side.
MIDDLE position (ie straight down) is MEDIUM
RIGHTmost position is OPEN, ie pointing to your left while riding.


(There's a chance I have that backward.  Test it out first)

So you need to set the lever to OPEN, and set the sag on your rear to about 25% when you're sitting still on the bike, with all your normal riding gear.   This is easier with 2 people.



You can press the small black nubbin on your pump to release air from the shock.  Its straight below your gauge in the first photo.  A brief press should make a Hiss and allow air out.

Some shock pumps have a two-stage connector, where the first thread engages the outside of the schrader connector, and then the second slowly lowers a "presser" into the release in the middle of the valve.  This is to minimise pressure loss when connecting and disconnecting the pump.


  At this point you should be able to release air from the shock, and add more by pumping.




I can't find your pump model - the nearest Giant is https://www.giant-bicycles.com/nz/control-mini-shock-1  but that looks quite different.

The manual for your shock is at https://www.ridefox.com/dl/bike/605-00-139-FLOAT-DPS-Tuning-Guide-white-revB.pdf