Actually, I always found PVC kind of a bother to weld as it scorches so easily. PE and PP are a dream to weld in comparison so you should have little if no difficulty. A feed tip is highly recommended as you are able to press the rod into the seam. And though air has been used, nitrogen is still the preferred gas medium, especially for water tight welds.
PP (and PE) welds a bit slower than PVC but gives you more control as a result. If you use natural color PP (which I suspect you will), the rod will turn transparent when heated and look like clear silicone squeezed from a tube. But it will return to a translucent state when cooled.
Though you will have to adjust your technique when you get a feed tip, you can use the tip you have now and weld free hand. The feed tip increases you speed significantly and makes a much better looking weld.
PP has what I consider a citric smell when heated. One way to identify it.
Of course, the best way to understand all this is to play play play. Have fun.