Head to Petpet Park Beta. Then click on "Play". Now you have to wait for the page to load. After it finishes loading, you will then type in your Neopets username and Neopets Password. At this point, you may get a "Could not validate neopets user". That means you will have to try later. If you don't get that message and got into the Petpet Park then congratulations!

Yeah, It's not letting me enter

I saw it in the neoboards the other day..
was wondering why its offsite.

I couldn't enter. I may try it later...