OT Landscapers best way to level a yard myself

Just bought a new house and recently added a patio. When adding the new patio the back of the house was built up which has now caused water to run to the back left corner of the yard and sit for days. The yard also appears to have a slight hump in the middle trapping the water from running to the right side of the yard to drain to the street like it should. My question is if I get some fill what is the best way to judge the slope without professional tools? I've read nailing together two 2x4's or 2 x 8's and having a level on top. Seems simple enough. Any other tips? I don't want to put in a drain because I will be putting in a pool within the next year or so. I would normally wait but because the water sits so long it causes quite the mess for the dog.