Create plane ground?

Hi,
i crate my own claim but ground isnt plane so i take my shovel an move some dirt
My problem is now, i have no idea what is the best practice to create an plane ground. I try special grid (crl+l) in elder client but all my work hade no plane ground as result.
Greets
i crate my own claim but ground isnt plane so i take my shovel an move some dirt

Greets