Yep. It'll pretty much open right away. If you are staying on-site, your 60 window will also extend to the rest of the days on your reservation as well so you can make selections for every day.
When you go to the FP+ selection page, you'll pick a date to make selections. Then you will select the people who you want to make FP+ selections for.
At this point, you can either select a park to visit on that day OR if you are on the website, you can do fast picks which could make auto reservations at random for a day, the entire trip or just suggest a park.
If you selected a park to visit on that day, you will pick the experiences that you want to experience. You have to select 3 of them per park. If you are on the website, after you select them and click Next it will give you the chance to prioritize those experiences.
After that, it will spit out 4 options for you to choose from. You need to choose one of them. Pick the one that closest resembles what you want to do. Once you do that and lock them in, you can switch out experiences or times on a per-experience basis within the app. Be sure to watch them because they may replace one experience for another (based on the prioritization they gave you). I'm not sure why they do it but usually if they do that, you can exchange out the experience that you wanted in the first place manually. At least in my experience.
Hope that helps! Have a great trip!
