The latest thread with the newest post on a topic board page will be towards the top of the page. The latest post on a thread will be at the bottom of the page (of the last page, if the thread has multiple pages).
If you have any other Community related questions, feel free to post and we will be happy to assist you!
With many threads that have many pages, new posts do not go automatically to the end of the line, if there are 14 pages and someone replies to a post on the second page, just entering the thread doesn't take you to the second page. If you don't want to search page after page for the newest post, leave the thread, click on the name of the last poster and go to their profile page and find their last post from there.