If you are serious about trying to get decent performance from your player, then there are a number of issues that need to be addressed.
Firstly, there is the issue of wiring and earthing, each component of the player, turntable, arm, cartridge needs to be earthed once and once only, if it is bought as an 'integrated' package this is usually taken care of. Just make sure that the connectors are firmly connected as is the earth lead if the player has one.
Secondly, the signal from the cartridge is at a very low level, any interference from other components will seem quite large in comparison, resulting in noise, usually a hum or buzz. This can easily be checked by moving the player away from the amplifier.
The most likely culprit is likely to be acoustic feedback, the music will cause vibrations in the room, in the furniture, whatever the equipment is sitting on, this is picked up by the cartridge, amplified by the system and causes a feed back loop.
Best practice is always to place the player away from the amp, often just to the side or a few inches above the amplifier is sufficient. It is also best that the player is supported correctly, ideally on a separate table or shelf. In either case the support should be as light and rigid as possible, avoid placing the player on heavy furniture, however solid you think it is.
Try setting up your system again using the advice in the thread however do not try and extend the signal leads from the turntable, this is not a good idea and rarely necessary.