Best thing you can do after a PPL is to go flying to the other side of the country.
You learn so much more this way (new airports, runways, windsocks (or lack of them)), different airspace etc.
If I had my time again I would actually hire an instructor to do this for my navigation exercises - i.e. go to the other side of the country and back in several days. Your brain will be fried and the AVGAS will cost more in the remote locations but the experience you get is worth it.
Take spare spark plugs, oil, aviation spark plug socket plus anything else likely to fail too (eg. rudder springs) and carefully plan with the aircraft operator regarding the maintenance release (50 hourly +- 5 hr oil change etc.) well before you go. And be flexible on weather (Nullabor Plain above Eyre Highway at 500ft isn't much fun... and watch fuel burn). So many lessons in such a short time!