How to add widgets to a theme?

I’ve recently set up a new wordpress site ( http://spicapublishing.wordpress.com/ ) but now I’ve discovered that their server can support wordpress so I’ve moved it onto that (it’s now at http://spicapublishing.co.uk/wp ), but the setup tehre seems somewhat different. I’ve also had some prior experience setting up a wordpress site for where I used to work (that site was on the wordpress.org servers though), so I know my way around a little bit.

The wordpress software has already been installed on the spicapublishing.co.uk server by the people who run it so I just have to customise it now. But it seems that some of the themes available on the wordpress.org server are missing, and some of the widgets are missing too.

e.g. on the spicapublishing.wordpress.com site I was using the k2-lite theme. The only one I can download to install on the .co.uk server is the k2 theme, which I guess is the full version? But when I installed that, some of the widgets from the wordpress.com site weren’t available (specifically the E-Mail Subscription, Image, and Twitter widgets).

Is there a way for me to put those widgets back into the k2 theme? I tried searching for a way to install them but couldn’t find one, and I didn’t see anything telling me how to do it on the main widgets page in the codex (and also, I’m not sure of the exact names of those widgets in order to track them down – e.g. there’s loads of twitter widgets around but I rather like the default one from wordpress.com ).

Sorry if this has an obvious solution, I’m just not seeing it 🙂 – any help would be appreciated!

EDIT: I’ve figured out the twitter one… so I need to add them as a plugin, then activate them?