For desktop streaming, Open Broadcaster Software (OBS) is highly recommended, as it’s free and fairly easy to use, but also deeply configurable. You can download OBS here.
For much more information on setting up OBS, visit their official help page here.
For something more straightforward (though lower quality in both audio and video), you could use StreamYard, which makes it easy to do more interesting setups like remote interviews, but you'll have to purchase their Basic plan to connect. If you’re streaming from your mobile, try Larix.
For more information on setting up OBS for Bandcamp, head over here.