Inside a post edit screen you will now have an SEO box underneath where you write your post.
You will need to write a specific META Description, Title and Keyword in each post in order to gain successful SEO rankings. This should also solve the issue with facebook showing the wrong title and description.
That other meta plugin you had may well have been causing this issue too.
In terms of changing permalinks, there are a number of plugins available to migrate permalinks for existing links that might be on google.
For instance if you have this link on Google now,
http://savingsupper.com/archives/499 and then you changed it to include the blog title rather than numerical it might cause a 404 page not found error when someone clicks on it.
The fact that you have only a few articles on your site right now means that isn't a massive issue so you don't have to migrate the permalinks if you don't want to.
Simply go into Settings__> permalinks in the backend of WP and choose a different preset. ALL your links will update and that's it.
Just make sure if you linked to any of your old posts you now change them to the new link structure or again you'll get some 404 errors.
Let me know how you get on!