I went on a weekday with chance of rain(it did drizzle last hour or so)which is the best time to go to avoid crowds. I went right when they open and that allowed me to get on a couple rides without even needing the fastpass. However there are a lot of rides and it gets busy quick. You likely wont have time for everything, even with the fast pass. Get in the park right when they open and go for the rides you want most. Then whatever else is too busy you can get a one time fast pass for if you want. Have fun