Never really got to learn about the old west, always thought it was intriguing though so I thought it would be about time to learn.
Hi, there's lots of room for more info from others, but you might be interested in this earlier answer from /u/kingconani
I've made a number of posts about this that you might find interesting. In addition to the one mentioned, here are two more you might find relevant to your interests. If you have any more questions, let me know, and I'll try to answer them:
To touch on some bullet points: Yes, bounties were a thing, as were dead-or-alive bounties. These were offered by both the state and private individuals or companies (often the wronged party, such as the case of railroads or stagecoach lines offering bounties for the capture of those involved). A bounty could also often be paid for information leading to an arrest and conviction. A bounty was not a notice of "open season," but applied to payment in the due course of a someone's pursuit and (attempted) apprehension. Those who pursued the bounties were often law officers or employees of detective agencies. I have not found any evidence for people who lived just by collecting bounties (though the Pinkertons would be about as close as you would come).
A key exception to almost all of the above is payment, often by the state, for Indian scalps. This was essentially license to wholesale slaughter, without any real examination of motive or circumstances. If you're curious what that was like, you can find an example in the Glanton gang, which operated as mercenary scalp-hunters working for the Mexican government, murdered Indians and were themselves killed in retaliation. (For more information on scalping, check out this extremely 90's website )