When FedEx is delivering a package to your home then they will make 3 attempts to deliver the package to your door.
If you still haven't been available for the package to be delivered then they will contact the shipper to find out what they want them to do with the package.
Most times deliveries can be left at the door without signing for it so for those they'll just leave at the door but if you need to sign for a package be sure that you'll be available and watch for the FedEx delivery truck during the time it's supposed to be delivered.