You can visit the Global-Player Casino as a guest just to look at the games and to try your luck. You don't have to fill in any forms or get any passwords, you simply click on "Guest games" on the main screen and you can start playing. Some games, notably multi player games, are available only for casino members.
If you wish to bring a guest to a community ritual, you should first get the permission of the people putting the ritual on. Please make sure your guest understands about confidentiality. Guests who are nonpagans or new pagans have special needs. Make sure that you talk to them well before the ritual about what they'll be seeing there. Explain the theme of the ritual, make sure they understand what will be expected of them, and take some time to verbally walk them through a ritual. And remember, once you and they are at the ritual, stay close to your guests and make sure they're ok. Introduce them around. Lend them a drum or a rattle if they're uncomfortable dancing. Talk to them afterwards and let them discuss the experience with you. Oh, yes, and teach them about grounding if they don't already know how; they'll probably need it.