It's not unusual for the Motion Templates folder to be empty if you don't also have Motion. Not a big deal. Just create the folders you need. There is one catch: you have to make sure that the Effects, Generators, Titles and Transitions folders are "localized". Create each of those folders inside Motion Templates, right click on each and Get Info (or select and type Command-i) and add ".localized" in the Name & Extensions textbox.
Each of the effect type folders are supposed to contain more folders which establish the Categories used inside FCPX. So before you try to install your effects, you need to create at least one category folder as well. (Categories do not need to be localized — neither do the effects folders.)
Effects in FCPX are folders containing several different types of files used by FCPX. There are two thumbnail images (large.png, small.png), a folder called Media (even if it is empty) and the Motion template (files ending in one of the following: .moef, .motn, .moti, .motr). There might also be an optional .mov preview file. The folder containing all these files IS the effect and it is that which you move into the category folder for FCPX. Do not change its name.
PS - you already have Motion Templates — make sure it is .localized as well or FCPX might not "recognize" it.