Hi, Natalia! Your vacation begins the minute you check-in at your hotel!
Chance are, your room will not be available when you arrive at noon. However, you can have your bags held for you, and you are off to play! The front desk cast member will give you a business card with a phone number you can call to check if you room is ready (usually around 4:00 p.m.)
Now, what to do the rest of the day . . . If you have park tickets you plan to use on your first day, you can head to the theme park of your choice. With your Saturday arrival, the parks will be open late, so you have hours to enjoy!
Another option: before you check your bags, grab your swimsuits! You can get some lunch and sit poolside and enjoy the Florida sunshine (bring plenty of sunscreen, Florida sun can be brutal!)
One of the great perks of staying at Port Orleans French Quarter is the boat transportation to
Downtown Disney. You can catch a boat right at your resort which will drop you off at Downtown Disney where you can spend the afternoon shopping, eating, designing your own T-shirt, or even see a movie!
Your first day can be a busy or as quiet as you would like! I hope this gave you some ideas on how to spend your first day of magic in Disney World!