Just got my invite before this beta weekend. I saw in the beta invite stick up above this line

"As a reminder to beta participants -- discussion of your participation in beta should remain in the official beta forums (outlined to you via email) and not within these forums.

Thanks"

Where are the official forums?

Also is the beta currently only doing weekends Or did I get just a weekend invite?

I'm new also. Pretty sure this is the Official forum for the beta

No, it isn't. The link to the official beta forum is in one of the invite e-mails.