If you have never joined an internet Forum before a little help might be useful.
It is a very simple process.
Click on 'Register' there on the first screen, near 'login' and follow the prompts.
You do need to have a valid email address because an email will be sent you in order for you to click on a link back here again - thus establishing that you are a real person and not some spambot, the scourge of forums everywhere.
And it should be said at the very beginning that joining a Forum, reading Forum posts and making your own posts in a Forum is absolutely without any danger to your computer. There is no security risk. Relax. There's no problem. You won't be downloading any virus or spam or malware or anything but the text.