This happened to me when i first installed the game on my laptop. The problem is that your your graphics configurations are too high and demand too much out of your processor.

If you would like to fix this, Open up the FFXIV Config launcher on your desktop (or in its rightful folder) and enter the "General" tab, there you will see a number of sub divided tabs, one being "Graphics". There should be several drop down menus that allow you to adjust settings from low to high (1 to 10) as well as a windower option. Under the Graphics tab you might want to drop your Drawing Quality down to "Standard" (5) or lower if necessary, as well as Background Quality to "3 or 4" and Shadow Details may as well drop down to "1" for the time being. Also in the next General Tab (maybe Details?) you can drop down Texture Quality and somewhere in there you should be able to turn off Ambient Occlusion.

Once you've done all of that, you may want to try messing with the ingame configuration menu and tweaking the graphics from there, but from my experience the off line FFXIV Launcher has a much bigger effect on lag and load delay.

If it still doesn't work well after all of that, then I don't know what to say.

I hope this helps. Good luck!