A lot of the other posts have touched on things like future use and different methods of working the area.
My front yard is some sort of greenish stuff part of the year. Can't call it a lawn. Winter it's basically brown with little apparent vegetation. Pock marked with mole runs, washouts, rocks that have risen ... sort of a mess. In Summer it gets rock hard and unable to be worked. Today I decided to try the landscape rake since the 'grass' hasn't appeared yet and then soil is soft-ish from rain. Set the rake as low as it would go. It cut off the high spots and dragged the spoils to the low spots, filling them in as I passed over. After several passes, I left the rake up and just drove around, packing it down with the machine and tire weight. Repeated that process of raking, then packing a couple of times. Also tore up the surface enough to take new grass seed (if I had any). It's a lot better than it was, but I may need to repeat the process after a few rains when I can see how it settles.
Remember, there was no growth more than an inch above ground, so I didn't have to deal with mowing first.
I'd say mow it as low as you can, then go at it when the ground is softer from rain, if you get any.
In my view, discing will turn up lots of dirt clods and make it rougher than it is until worked further. That may be a necessary first step though.