You won't be "in transit." LAX will be the port of entry into the USA and you will clear US immigration and customs at that port.
Your next flight will simply be a domestic flight from LAX to MCO.
You will be fingerprinted on arrival as part of the normal immigration process. Your Visas (if required) and any necessary authority to travel (such as an ESTA) will have already been obtained by you in Singapore well in advance of leaving.
With that length of layover you should sensibly allow 2 hours after arrival to clear immigration and customs. Similarly you should allow at least 2hours to be at the airport prior to your onward flight to MCO. There are plenty of hotels ( at all price points) near to LAX to get some rest in the intervening 9 hour period.
Given how busy and spread out the area around LAX is, I wouldn't plan on achieving anything else until you arrive in Florida. Your school should then be able to direct you accordingly.