Regs and requirements vary by location, but many years ago I did a 10x20 patio with my dad. We did all the work - subbase, tamping, joints, screed, float - except delivering the concrete. Truck backed up, poured it out, and away we went. It passed inspection and is still in use by the current owners.
The point being, you can do a pad yourself, but you need to do your homework ahead of time and have at least one helper. YMMV.