I'm sorry, I'm still pretty confused I am very new to this. When the accelerometer is stationary shouldn't the output be 0g?
No, because some part of it will be racing towards the centre of the Earth.
Or it would be, if the Earth weren't in the way.
If your accelerometer is not exactly at right angles to the perpendicular (which came after Norman, IIRC), then there will be a component of acceleration due to gravity.
Presumably, dangling an accelerometer arbitrarily on a frock, it is going to be difficult to keep it level at all times, so you need to work out which way is down.