Firstly.. Welcome! It's great when new people come aboard. Has your lil gecko got a name yet?
You'll have people throw all sorts of reptile names at you after asking such a broad question haha. Truth is, a lot depends on you and your needs, what you're willing or not willing to do or deal with. Some people here even started out with pythons as large as olives or scrubbies and they wouldn't have it any other way, but those people generally were passionate and confident enough and had enough space to manage.
Are you looking for a snake? If so, do you want something that's going to stay pretty small like a spotted python, or something that will get a little size to it like some of the carpet pythons?
Or maybe some more lizards? I'd definitely recommend blue tongues if you're after another lizard.
Personally, my first reptile was a cape york carpet python, followed closely by a hatchy water python (water pythons tend to get a very bad rap, but mine is a sweetheart). Typically you'll get quite a few people recommending snakes like Childrens pythons, Stimmys, Spotteds and different Carpet pythons to beginners. And they definitely make a good point, but make sure you look for something that's going to suit your situation and something you love, because reptiles tend to have a decent lifespan. Also, best tip anyone can give you: Do a LOT of research before deciding on any new critters, no matter how highly recommended they come. You need to know what's going to be required of you if you're to be responsible for another life.
Good luck! Let us know what you decide