It should have a tone arm, which has the needle and a kind of brace that balances the record above the turntable.
You can play one record by putting it on the turntable, and either moving the tone arm by hand and setting it down gently, or by setting the record on the turntable, and turn the knob past the start position to the change position and the tone arm will lift up, and move to the first track of the record and start playing.
If you want to use the record changer, you can position several records on the spindle, there's a catch that holds the center up, and move the brace over the records, and set it down. It will hold the records steady, until you're ready. Turn the knob to change, whatever they called it past the on or start position, and the first record will drop, the tone arm will move over and start to play. When it finishes the last track on that side, the tone arm automatically lifts and moves back, and the second record drops, and the tone arm comes back to the first track and starts again.
I'm guessing you know about the speeds, they should be on the records, but the smaller ones are usually 45, the 12 inch ones are 33 1/3, and if you have 10 inch ones they are probably 78s, be real careful with those, they're made of wax and break easily.
