Sorry to hear you have problems. All may not be lost.
During shipping, some connections may have come loose.
Did you get manuals and discs? What are the computer specifications?
Disconnect from the wall socket, open the case and make sure all parts are seated properly, IE, RAM, video card and any other add on cards.
Check that all the cables are properly plugged in.
Check that the clear CMOS plug is on the correct pins.
Check that the monitor is connect to correct outlet on the video card, the 2 screws should be done up firmly but not over tightened.
Leave the case open, connect back to the wall socket, start the computer and enter the BIOS. Check that all the fans are spinning.
Set the correct time, date, region and language.
Go to the exit menu,
Highlight, load defaults,
Highlight, save and exit,
Press enter, press OK.
The computer will restart and hopefully load the OS.