I would like to recommend that you work through this tutorial in a step by step manner as if you choose to do that all your questions will be answered in a logical sequence. http://learn.wordpress.com/
After I set up my two blogs, I clicked on saved and it flashed published. Does that mean it's out there for the world to see?
1. When we create a post or a page and click "save" we have created a draft post or page that cannot be viewed by others on the internet.
2. When we create a post or a page and click "publish" we have created a post or page that will be on the internet and can be viewed by others, unless the blog visibility setting is "private".
3. Whether or not we have created a draft post or page and "saved" it, or we have created a post or page and "published" it in a public blog or in a private blog we can edit always what we have created.
Do I have to use posts and tags? I don't understand what they're for. Do I use them on all my blogs? I also noticed the word uncategorized in my blogs. What does that mean? How can I get rid of it?
When we create posts we can assign Categories and Tags to them. The default category is Uncategorized, and we can replace it with another Category we create if we wish to, but we cannot have a blog that does not have a default Category.
If you want your blog content to be found by others on the internet then Categories and Tags are important. They work the same way they do in a library. When you want to find books on particular subjects in a library you use the Index or Catalog and search for categories and tags that lead you to the relevant books on the subject matter you are interested in.
Change the word "books" to "blogs" and it's the same for those searching on the internet for blogs on particular subjects. They use search engines to search for blogs on particular subjects. If we have assigned Categories and Tags to our posts then they will be found in the search engines indexed results. if we do not use them then how will our blogs be found by readers who are interested in the subjects we blog about?