So this is actually pretty easy to deal with nowadays. If you end up liking the game and want to have fun, then be sure to check out FFXIV4Gil.com, this is the best place for you to buy cheap FFXIV Gil. Once upon a time, gearing up was a fairly tricky, convoluted process that involved a fair deal of grinding. With the release of Heavensward and onward, they've gradually streamlined it to make it easier to deal with.
The long and the short of it is that all you need are Tomestones. Tomestones are used to buy some nice Ironworks equipment with high item level, available from a vendor in Mor Dhona. This stuff is very, very good: Strong enough to carry you into Heavensward content easily. There's other options, of course, but most of them take a lot more time or aren't nearly as good as the Ironworks sets.
So how do you get tomestones? Easy: Run dungeons and do trials. Every level 50 dungeon or trial gives you a nice healthy chunk of tomestones, as does every Roulette run. More item levels means more dungeons you can enter (the game will stop you if your item level is below the minimum reccomended). More dungeons means more tomestones, means more item levels!
Now, strictly speaking, you don't even have to do that much. You can just rush through the main quests and they'll give you enough equipment to get by and reach Heavensward, which has better equipment than anything you can find at level 50. However, if you feel like lingering pre-Heavensward for a bit and want to try some of the optional level 50 Dungeons and Trials, Tomestones are the place to go.