Let hope that my website is good enough lol. To be honest, I am not exactly sure what to say.

treat it as a project - do your research into what they want - check out their site for the type of content and wher you would see their site going with the type of content and how frequent they post
read their bio's and see what they are like.
as long as you see yourself fitting in with those people be natural, but do have a script you have prepared before recording the video, don't keep looking at it or straight at the camera. give yourself thinking time - but no 'er's' or 'umms'
tell them what you have accomplished - setting up a site in wordpress, learning seo, able to get posts onto page xx of google, knowing google analytics, how to use the data.
improving pages, other tools you use to get info for new ideas - don't reveal names but types of programs.
how you organised your site - and content - how far ahead you were planning your posts. did you accomplish your plan - how did you cope with emergencies
what you think of their site and how you could improve it
what are your plans for the future.
there are lots of ideas, so plan out what you want to say. write it down. when you say it don't just mechanically say it - say it with feeling.
listen to what you say - if you don't like it -re-record it.
so overall
who are you
be brief
what can you do
list down your skills
what can you do for them
how can you do the work they want
how can you improve their site
what do you want to see on their site
just a list of ideas
but mainly be fairly natural
and have fun