leveling up

windtourer

ok, just bought my first motor home. It's 19 ft long about 8 ft wide there's me and the misses spirit level in hand leveling blocks on the ground and not wanting to look a right xxxx how do ya go about it. We have a table mid ships ish do we take readings
from here, we have a rear galley do we take the reading from here at least then we'll know the fridge is level. Do you level left to right ,front to back