some problems in elgg

hi all,
I've tried installing elgg on process has been successful. but when I try to be a member of my site (the new user registration), I got the message in order to immediately verify the email to activate membership. but, after I opened the email, I can not find the confirmation email.
The next problem is how to install plugins and themes in the elgg.

please help me with this problem.

I hope, elgg can provide a more detailed installation guide.

chepy amiraga