Jack it up, car jack, bottle jack, FEL, put it on bricks, blocks, frame and pour concrete(if you haven’t played with 10-11 yds, pay the man) concrete waits for nobody. Even if fiber mesh put in wire. I wouldn’t worry about plumbing can always do later just put plumbing on top of concrete and build floor above it for bathroom, shower etc
It would make life mighty easy to plan the bath and stub in drains when pouring .
