SoundCloud Go is a subscription service. Any tracks appearing on your profile and/or available for that service will potentially show up or not show up in full unless you use SoundCloud Go as a subscriber.
SoundCloud Monetization is for you to monetize the music you have on your profile with ads displaying before playing it.
In order to monetize, you must have your profile whitelisted through Symphonic, an agreement with Symphonic, and a spreadsheet filled out after Monetization is enabled. We can, in some cases, grant the ability for you to monetize directly on the Soundcloud profile as well but this is approved on a case by case basis.