Yes, some cards are aimed at more established people. I think a good general rule is the higher the annual fee the harder it maybe to get.

Not always the case. As they give away the AMEX plat. But I would just say start with a solid fee free card like Chase Freedom or one of the discover/citi card's that are free and go from there.

Look at the benefits cards give out the more there are the more they are aimed at higher income people.

Pay attention to issuer like AMEX, Chase, Citi, Discover, barclay, etc. Start to build a relationship with their lower tier cards (fee free cards). That is always a nice way to make sure you qualify for their higher cards.