When you are in a relationship, better not to dive into the world of marriage immediately if you are not mentally, physically, and financially ready. It doesn't matter how long you are going to wait or how quick you'll decide, it solely depends on you and your future partner. If you are ready to get married, but you aren't sure if your partner is the "one" for you, you should think about it first. Marriage isn't something that you can decide on a whim! If you are ready and you think that your future partner is the "one" for you, then do it. It's only natural to be naive because it's not like you get married every year! Everyone starts that way especially those people who are concerned about future events.
If you're ready, decide for yourself whether you are going to wait longer or not. It doesn't matter if it's a month, a year, or more.