Hi, Jody!
Greetings from your neighbor to the south, and welcome to the Disney Parks Moms Panel!
Online check-in is such a useful feature as it allows you to bypass the front desk and go straight to your Resort hotel room, provided your room is ready when you arrive. When you complete your online check-in, you have the option of receiving a text message and an email notifying you when your room as all ready. Official check-in time can either be 3pm or 4pm depending on which Walt Disney World® Resort hotel you are staying at, your room isn't guaranteed until that time. However, you may get some pixie-dust and your room become available early.
If you are driving in, simply present your MagicBand and a photo ID to the security officer at the entrance gate, all Resort hotels have a gate for guests to stop at before entering the Resort's property. Once they have confirmed your reservation and scanned your MagicBand, you will be presented with your a parking pass, if needed - some Resort's still use parking passes, but many no longer do. When in doubt, just ask when you arrive if you need a parking pass. If your Resort hotel still uses them, it will be waiting for you at the entrance gate.
I hope this helps, Jody! Please let me know if you should have any additional questions. I'd also love to know where you are staying and I can confirm if they still provide parking passes, or if they have a MagicBand enabled entrance gate in addition to the security gate. Hope to hear from you again :)
Faith