It's no secret that much of the points/miles game is played by signing up for credit cards - the signing bonuses on many of the most popular cards (i.e. Sapphire Reserve, Amex Platinum, etc) are enough to get you started on planning for special trips pretty much anywhere. But the caveat always is to make sure you manage your card spend wisely. This article from Marketwatch is especially pertinent:
The numbers are a bit staggering. $870 billion in debt is downright awful. The best advice - pay off your card every month. If you can't do that, then you probably shouldn't use one. The only real way to get value out of the points you gain is to use cars for normal, everyday spend. If you were already going to the grocery store, then you might as well swipe to get the points. And please don't use a debit card - they are notoriously bad for security and get you nothing but a live feed to your checking/savings account that could be compromised.
If done properly the points/miles game from cards can be profitable and open the door to many trips - be smart and play the game the right way!