@sitharus honestly im not an audio expert or anything but i know the basics.
basically you need 4 components in an audio system, the player, the pre amp, the power amp, and the speakers.
Id reccomend getting an integrated amp as they have both pre amp and power amp.
(Again not an expert u should probs google this) to check if an amp has a built in pre amp look for phono inputs on the back, if it just has Line or aux inputs give it a pass.
Phono is what your player commonly outputs.
@sitharus if ur buying used integrated amps they go by other names too: receivers are basically integrated amps + radio tuner, av receivers are integrated amps + video switch.
If you go on ebay you might have to vary your search terms a bit.
When deciding which one to buy, just look for one in your price range and google reviews and specs. Theres bound to be some info.