If you look near the bottom of the thread you are interested in, there is a line (under the 'Post reply' button) that says 'watch this topic for replies'. Click on that, and then you will be emailed when someone responds to the thread.
I think that option is also a tickbox when you enter a comment on a thread, so check that and it will automatically send you notifications.
Then, if you want to stop the notifications, you go to the same place at the bottom of the thread, and the 'Watch topic' will magically show as 'Stop watching this topic'.
Also, if you click on your name (i.e. from one of your posts), it will take you to a screen that has your basic information. Then you can click on 'see all posts by Earth Intruder', which will take you to a list where you see all your posts, which can be clicked on individually, to go to that particular post. You can also do this on other people's names, if you want to see what they have been posting.
And welcome to WP. 