To join the WA, first you will need to have an email associated with your account. To do this, click the 'Settings' button. This may look different if you are not using the default theme or mobile, but the general steps are the same, they just look slightly different. Send me a TG, or make a post on the RMB if you get stuck.
After you click the settings button, scroll down to the email part of settings, and add your email address.
Remember to click the 'Update' button at the bottom of the page when you have finished so the email address is saved.
After you have saved your email address, navigate to the 'World Assembly' button and click it. Saving your email address also allows you to recover your nation if you forget the password, which happens all the time. If you don't have an email with your nation, you've generally lost it forever.
Once you are on the World Assembly tab, click the 'Apply to Join' button.
This should open a page that looks like this, which will basically explain to you that to join the WA you have to go to your email, and click accept, and to look inside your spam folders etc. for the email. It is usually pretty fast to arrive, within a minute or two.
After you see the above message, you should navigate to your email, and find the email. It will be from some generic email, mine says it is from 'Nationstates' sending from 'firstname.lastname@example.org'. It should be in either your main email, the updates tab (for gmail) or it may have tripped the spam filter. The email should be there reasonably quickly. Once you get the email, click it and open it. It should look somewhat like the below, asking you to click the link to allow acceptance into the WA. Click this link.
Once you have clicked the link, it should open up and present a page like the below. Click confirm.
It should show a page like the below. Congratulations, you are now a proud member of the World Assembly!
To do this, open our region page (open this link: The Pacific) and click the delegate nation and the top of the WFE.
Once you have opened the page, you should be confronted with a normal nation page. Scroll down to the bottom, and click the endorse button. The reason why you need to do this is because our region, like all great powers, has slippery enemies who wish to control of the region, and destroy us all. Every endorsement our Emperor is a stone in our wall against those who seek to destroy our region.
Once you have clicked the Endorse button, the page should change, and the button should have changed to the below picture. This means your endorsement has been successful. Once you have successfully completed the steps above, you are eligible for citizenship on our offsite forums (found here: http://ns.npowned.net/forum), you can be endorsed (the limit is currently 10 endorsements in the Pacific, exceeding that results in a warning, and then a subsequent ejection from the region, which results in your nation becoming located in a place which some have compared to hell.),
and you can vote in WA resolutions. Please don't push people over the endo cap.