Hand me downs are usually free. Try not to spend $$$ just to evaluate what was free. Granted, Sylvania is an older Company. However, if you are new to audio, you have to start someplace. If you can connect them and they work, GREAT. If you can remove the grills to see the condition of the speakers, even better. Usually with old speakers, the surrounds rot. So where the cone connects to the basket near the outer edge, their may be a corrugated area or a rubber looking element that helps the cone move in and out of the electro magnet in the center of the basket. Another thing to observe is to lightly touch all 5 fingers, as evenly spaced as possible, of one hand to an area near the center dust cover in the middle of the basket and press lightly. The cone should press in by tiny amounts and you should not detect any resistance at all. Don't press hard.
If these terms make no sense, look to YouTube for an explanation of a speakers components.
It's good to hear someone is curious.