Walk the site before backing in and identify the low side.
READING GUIDECAMPSITE SETUP
How to Level a Travel Trailer at a Campsite
A practical sequence for levelling, chocking and stabilizing a travel trailer without confusing the jobs each component performs.
Level the trailer side-to-side with the wheels supported, chock it securely, then unhitch and level front-to-back. Stabilizers are normally for reducing movement, not lifting the trailer into level unless the trailer system is specifically designed to do that.
What matters in practice
Use rated levelling equipment under the wheels rather than improvising unstable stacks.
Chock before unhitching so the trailer cannot roll.