A good credit card offers good benefits and miles credit cards are the best. There are airline mileage cards and they come in two categories. One is given by an airline that can be used only for that airline so if that airline does not fly into your neighbor hood airport, that is useless to you. The other you get from a bank and those miles can be used on almost all airlines.
To obtain these miles, you get some when you apply of course called the application miles bonus, then there are the miles you get per dollar you spend and the miles you get for the miles you travel. But do read the fine print and find out if there is a limit to the time in which you need to use these miles. Some give you years and some never expire.
The benefits are for different levels of of privileges and the one advertised is probably the highest level, once again, read the find print or ask questions. Annual fees can be high enough to out weight the benefits. Some card cost you $25 a year just to have the card in your wallet and other can be as high as $180. Interest too can be a little higher than regular cards and all this might make owning one not worth the money.