Hi tspoiled,
Welcome to TSG!
At power up of a computer, it usually is directed by the contents of the BIOS which pressing F2 usually means (like on my desktop) that when you press it, it will transition into the BIOS where you can set the order of boot devices like a floppy drive, CD or DVD, hard drive (disk).
Check the boot order of devices in your BIOS when you next reboot to make sure that it is set properly.
Make sure that it has CD or DVD first (assuming your laptop has one of either CD or DVD), then next should be the hard drive disk (assuming you do not have a floppy drive).
Then exit the BIOS and save the boot order (only if you changed it), and then the laptop should continue rebooting.
If you do not have a CD from which to boot (like a Live CD or installation CD) in your CD or DVD drive, then it should boot from your hard drive disk from the installed OS.
It may be telling you that you have a boot order that only has one item (the rest disabled), and that may be your CD or DVD drive. Again, look at the boot order in your laptop's BIOS and make sure you have at least a CD and HD disk in the boot order - in that order.
If you can login to your laptop, and get into your user account, why would it tell you to press F2 at that point, and then ask you to insert a boot disk? Unless, the login you are performing is that your laptop has a boot password that you must give after you power it up - is that the case - i.e. is you laptop protected with a boot password in order to boot up your laptop?
-- Tom