So you found yourself with a stereo. Maybe a parent's system, maybe an estate-sale pickup, maybe a relative decided you are the one who knows about this stuff.
Good news: most of it is worth keeping. Here is the order I would do things in.
Look first. Open the lid if it has one. You are looking for leaked batteries, rust, pet hair, or a belt that turned to tar. Smell counts too — anything burnt means stop and ask before powering on.
Then power. If it looks clean, plug it into the wall by itself, volume down, no source connected, and let it sit a few minutes. Loud hum, a hot smell, or flickering lights means unplug it and post here before going further.
Clean second, fix third. A scratchy control or a dead-seeming channel is usually dirt, not damage. Contact cleaner and patience fix more "broken" receivers than parts do.
And take photos — the front panel, the back panel, and the label on the back. When you ask for help in this category, those three photos answer half the questions.
So: what did you inherit? Post the brand, the model, and the story. Then tell us what you want it to do — play records, stream, or just not get thrown away. That answer decides everything else.