To log into your Rec Room account, recover your password, manage your email / notifications / custom room settings, please visit Rec.Net
Yes! You will be in the same games as players on Rift, Vive, Windows MR, and other headsets by default! If you would like to opt in to only playing with other PSVR players you can find this option in your watch menu > Settings. However the only people available in this mode will be other PSVR users who have selected this option, which will likely be a much smaller pool of players.