Once your credit score is good enough you'll get approved for "good" credit cards, then get benefits with them I don't make the most of my benefits, some people truly min/max the whole thing and get enough points for free flights + hotel etc... Takes time though, I'm not that serious about it.
Oh yeah if you have a business, or even just travel a lot for work, that will get you a ton of points lol
As many companies get you to book your own travel then reimburse you