No Worries you'll figure it out

If you look at the bottom of someone's post you will see the words
Like, Quote, Reply, and
Top.
Like and
Top are the easy ones, Top takes you to the Top of the page and you click Like if you Like what someone posted.
Reply is what I did here, it adds your post to my post and it sends you a notification that lets you know I replied to your post.
Quote is just like Reply, but you can click Quote on more then one post.
Once you click Quote you then go to the bottom of the thread where you can start a new post, on the bottom left side of that you will see it says insert Quotes.
You can click insert quotes and then add or delete the post you want to add to your post.
Did you get all of that

LOL You'll catch on
Another thing if you want to make sure a certain person see's your Post you can type
@ then that person's name like this
@LoLoThatIsMe123
If you do that they should get a notification telling them you mentioned them in your post