Hi timetowork. Welcome to the forums.
how to view my previous post
There are various ways, but up in the top right corner of the screen you will see your username (if you're not on a mobile app). If you click that, you can view all kinds of things relating to your account, including :find latest posts" on the left.
Also, on each page there is a link in the main menu called "My SitePoint", where you can see the latest activity in threads you are involved in.
You can also set your account to send you an email each time there is new activity in a thread you've participated in.