Hi, for some reason I can’t pvp, even I have wifi… i tried to pvp a several time. 
Do you have at least one arkadion at lvl 20?
If so, can you tell us what it says when you try to get in? Or provide us with a pic, whichever is best for you.
It says “searching for opponent” it took forever then the search cancel.
Sadly In the lower tier of PVP it often takes a few tries to find an opponent. I went a few days without getting a match when I was there.
Moralol is correct; you should be able to PvP, it’s just that no one’s there at that time.
Sadly I tried everyday, and still can’t pvp.
You may want to wait on PVP until the patch comes out sometime this week anyway…unless you’re ready to fight gold/evolve hackers with a full line of S Class Fusions. 
^Most S class fusions are easy to get. I have a few S Plasmodius and Skullwraiths lying around. S Shadowlance and S Plasmorex aren’t too difficult.
…S Angelon is very hard, though. Like…very hard. S Dreadwolf was easy…I used a grade boost for my Omegawyrm.