Well hi there, I just happened to get a google alert linking here since you used New 2 WP in the thread title, as http://New2WP.com is my site. Usually I get them for pingbacks, so I came to check who was linking to what on new2wp.com.
But you are just New, to, WP. lol. I see that you aren't getting any answers, so here's some.
There are over idk, 40-50,000 free plugins available in the WP plugin repository, you can find more than one for everything you want/need to do on your site. If you go to your WP dashboard, click Plugins in the left nav, then Add New, there you can search for anything you can think of and you'll find a plugin for it im sure.
1. So, go there, search for Twitter Tools, click install, go to the Settings > Twitter tools page and configure the plugin. Thats done.
For facebook, I use an app on facebook called Social RSS that's pretty good and easy to use: http://www.facebook.com/apps/application.php?id=23798139265
Add that to your facebook page, go to the edit settings page for the app, and enter in the RSS feed of your blog which is, http://yoursite.com/feed, configure the rest of the app and your all set.
2. WordPress has built-in api support for most major video sites. So you can simply post a URL of a youtube or vimeo, etc. video into the post editor, and it will display the video for you in the post. But, if you want to have more control, I suggest installing Viper's Video Quicktags. You can search for and install that through the dashboard the same way as I explained above.
3. Search for the plugins, Twitter Button, and FBLikeButton, I used those on New2WP for my buttons, until I wrote a tutorial on how to make your own social buttons http://new2wp.com/rookie/create-social-bookmark-buttons/
You should check out http://new2wp.com/levels/noob/ and http://new2wp.com/levels/rookie/ too, posts are organized by level of experience with WP, you may find some more useful stuff from the posts I've written.
Welcome to WordPress!!
It's now the beginning of forgetting all about droopla for you :)