OK, I would want to be a Terminal 3 by 9:45 AM to check in luggage, go through security, etc.
A 7:48 pickup gets you tot he Disneyland Hotel for the 8 AM departure to LAX, and takes about 1 hour to get to Terminal 3, the 8:48 AM would get you on the 9, and there at 10 AM ish.
So for safety, I would opt for the 7:48 AM to add some time in case of traffic delays, and then expect an extra half hour to "kill" in the waiting area after the TSA security check, lots of options for a late breakfast. Gladstone's 4 Fish is a good option.