I am a moderator but it doesn't take a moderator to answer this question:
Often the first post that someone makes is an introduction post. Check out the list of subforums for the right place (I think there's one called 'introductions").
Let us know who you are - you can use your real name or the user name that you've chosen
Let us know if you have a gecko, more than one, or if you're thinking about getting a gecko
If you do have a gecko, it's always lovely to share pictures
Let us know if you have any questions and what you're hoping to gain from being part of the forum
Most likely, some people will respond by saying "welcome (I know I will).