Check the International Time Standard frequencies, such as 5.0, 7.335, 10.0, or other beacon type transmissions to determine if your radio is functioning. Compare realtime notes with a friend having like hobby interest. You may simply have an issue which is known as 'Operator Error'.

There are a multitude of issues which may contributing to your lack of reception at any given moment. All are subject to change. Local time of day/night, season/current weather, frequency of operation, type of antenna relative to a given portion of the radio spectrum, antenna orientation, antenna gain, receiver sensitivity, selectivity, ionospheric conditions, sunspot activity, conditions at remote locations, are just a few issues that come to mind. I suggest you obtain a copy of an ARRL Antenna Handbook. Learn the basic principles, and then experiment with antenna construction. One of the best general purpose omni-directional antennas, to start with, IMHO, is a Discone Antenna. Once you listen, you can ascertain where a station is located, flip your Antenna Selector Switch from the Discone, over to a Beam Antenna, such as a Log-Periodic. I've even used a very large TV VHF/UHF antenna/booster with a medium antenna rotator somewhat effectively. Remember, there are second and third harmonics. But simply connecting to a set of bedsprings can serve the purpose. Longwire antennas are suitable, up to a point, but damn inconvenient, when it come to trying to change the orientation. !!! Be sure you rule out 'operator error'. Shortwave listening can be enjoyable, but very challenging; especially if you forget to connect the radio to the antenna.
Since antenna theory and construction rarely, if ever, changes, you don't need the latest handbook edition. About all that changes, is that someone may develop a different type of antenna, or improve upon an existing version.
I'd suggest you obtain a quality commercial shortwave receiver, and a good antenna tuner, to match the receivers' impedance to that of the antenna. Antennas are only efficient with-in a certain portion of the radio spectrum, and the tuner helps maintain that efficiency. Tune for maximum signal, even if initially it's only background noise, as you tune across the dial. There are several good reference books relative to frequency spectrum content, World Radio TV, Pirate Radio Stations, etc.. The internet has a wealth of information available. You never know what you may hear. How about being the first to hear 'Sputnik', or ground-air 'SkyKing Do Not Answer' transmissions to flying USAF command post aircraft, or International Space Station communications. If you're 'up to the challenge', you can become an Amateur Radio Operator, and convert from shortwave listening, to actually operating 'On The Air'; within authorized privileges.