I have always been asked do i need an expensive studio to broadcast on the station.
the answer is , depends on your budget.
Yes you can broadcast using your USB mic, but might find it hard to play music, thats what i found.
or you can invest in a mixer, these have a large price range. but I found that if you say want to play CD, records and a microphone. then a cheap mixer is fine.
A mixer with at least 2 stereo line inputs is good.
So how do i connect this to my pc/laptop? well if your using a desktop some will have a sound card on them, use the blue socket this is line in, from your mixer output. don’t connect to the mic socket it will sound crap.
If your using a laptop you will find that this will not have a line in socket so you can use a usb soundcard with line in cost about £8 ebay.