I really don't get the continued GPS Nav fear and loathing.
Accepting that nothing should ever stop you from making a good plan having the GPS there is eminently sensible isn't it?
After all isn't the OP a low time pilot looking to learn as much as possible? My advice would be make your manual plan and relate your accuracy of flying that to the GPS Nav.
In the end quite frankly what is lost to many is that once you have been at it a few years flying VFR is largely done from memory of having done it for those few years...
Its all very well suggesting that the GPS can fail but how is that so very different from a low time pilot getting lost. Then what happens? Fuel gets low, panic and stress sets in and before you know it a perfectly good aircraft is in trouble, maybe even put down in a field.
IMO it should be compulsory for low time pilots to fly with GPS nav as a back up all the time.