Well at least you know somewhat the history of the jeep. I hope he stored it well for you. If not, you may need to drain the gas, if any, out of it and put in fresh, along with some gas treatment that will dry out any condensation and clean the injectors, ect. Change out all of the fluids, even in diffs and transfer case, transmission, ect. Battery may be shot after sitting that long. Have it tested or just put in a new one. Plugs, wires, and rotor and cap may need to be replaced. Are your tires dry rotted after sitting that long? Check them out. Could have a blow out if they are dry rotted.
Good luck getting it up and running, and welcome to the addiction.
We like pictures.