Hi Amy - great question. As a past moderator in another forum, my advice would be to keep a thread on topic. Normally it means if what you have to share is or is closely related to the topic, then you are on topic. If not, starting a new topic or doing a search to find a thread to add to is the more appropriate approach.
As a newbie, you should probably familiarize yourself with the guidance and rules here. I also suggest reading the sticky notes (you'll see these attached to various forums you visit; e.g. modern coins/currency, classic coins/currency, errors/varieties). Many good tips can be found there and expanded discussion on common topics. Using a Search or an Advanced Search here will also help you to find topics/examples you may be researching or looking for.
And you can always post a moderator here with a question: they are quick to respond (usually get more than 2 responses to a single query). Folks here are very willing to help you along the learning curve to help you enjoy the forums and the hobby alike.