At the bottom of each individual post to the right side are two buttons, one is labeled “reply” and the other is labeled “reply with quote”.
If you click “reply with quote” a text box will appear with the contents of the persons quote that you are responding to, their post will begin and end with the word “quote” inside these brackets, this is what creates the box with their words appear in your post.
I just did that so your post appears in a box above what I am writing, if I only wanted to quote part of what you wrote I could have simply put my cursor after whatever I wanted to leave out of your post and backspaced until the part I wanted gone was deleted like this
I backspaced out the extra line after “I” in the beggining of your post so it reads better and removed the last part about setting up a blog.
The bracketed “quote” you see when you are writing is not visible in the final post, it is the “command” that tells the website to create the quote box and when the text portion in the quote box should end. The syntax is crucial for it to work because the website only recognizes the correct commands, anything else will just appear as a typo in your post.
Clicking the “reply with quote” button creates these bracketed commands automatically but you can create them yourself at any point in the post like this;
This is just me continuing to type but I placed the word “quote” inside these symbols before starting this sentence and I will end this sentence with this “/quote” but inside these symbols  instead of quotation marks so this quote box will end right here
This is a good thread to play around until you get it, it is pretty simple in spite of my explanation that is probably making it sound more complicated than it is.
As to the personal blog question, I am not sure if you need to hit a certain number of posts or a time frame to create one (a mod will probably see this thread and answer that) but how I usually do it is I decide to blog something I wrote in a thread by clicking the “Blog this post” button on the lower left side of my post after I have posted it in the thread.
It will take you to an editable page with the entire post that you can add or subtract to in order to make it more of a stand alone piece, when you get it how you want it you just click the button to blog it and it will be saved as a blog under your user profile.
Sometimes I write pieces on a word processor in my spare time and when they are ready I go to my profile and start a new blog post from there and I “copy & paste” the contents of the word document I wrote on my computer into the blog text box. Just add the title and submit it after that.
At the top of every page on RO is a button labeled “member blogs”, clicking this will take you to a page that shows all the recent blog entries from our members, if yours is recent it will appear there for all to see.
If you like the blogs of other members you can click a button that says “subscribe to this blog” and you will get a notification whenever they post something new and others can likewise subscribe to your stuff.