As for "waiting", you can get near most FP distribution areas before opening at DCA, but at
Disneyland, only those in Fantasyland and Tomorrowland can be accessed, as the rest of the park is not open until official rope drop.
And also, Frozen is currently not offered. (Stand by only). So for DCA, I would do either ToT or RSR and then go get the WOC FP, since it is disconnected.
For Disneyland, I would opt for Space Mountain as my first FP of the day. And then ride Space Mountain in Stand By so you can get two rides.... And grab the Star Tours FP before using the Space Mountain FP (based on the time printed on your first FP)
The usual wait at opening is 40 minutes after the request time.