As someone who solo'd ARC most of the way to 50, Stoneskin + Cure + Protect make your life much easier.

For the chocobo, you must first join a Grand Company and then pay 3000 company seals (currency awarded for doing work for the company). To join you have to progress along each company's quest line until after you see each leader give a speech, then continue one questline further until you are officially inducted.

More precisely: look at the chart here. You have to complete all 3 down to the 5th line, then any one of the 6th line quests. The 7th line is a tiny quest that you complete by being formally inducted. At this point you will have 2350 seals. There are many ways to earn seals, but the fastest way to get to 3000 would be to complete the Grand Company side quest Imperial Devices with a few friends or a single higher-level player.

For all the basic information on grand companies, check the Lodestone page.