Yeah, the PP points are what shows the player's skill, since it's really hard to maintain, haha.
Although some people complain about the system (like me, lol) because after a bad losing streak their points can go WAY down. like for example, I had just under 3000PP then got dragged under to 1500PP and am now struggling to hold onto the 2400PP or so I have now, lol
I would only play on endless (player) matches for now if you're playing online, or even play through arcade to familiarise yourself with the game, or people's moves, see which character you like playing as the best, etc.
You could even play endless with me or meow or DHG sometime, we could help you learn by showing you stuff that online players tend to do and we wouldn't just beat you up in 10 seconds so you don't learn anything, lol. Or you could watch us play, something like that.