If you are interested by advanced antenna setups, i advice you to enter the Ham radio world (amator radio) through Internet searches and forums.
There are lots of readings available, software tools, schematics, books on the subject and a lot of friendly guys with very advanced knowledges.
Antenna setup for wifi is not very different than general radio rules, and hardware for setting up antennas is not different as well. You will find in the Ham world all the tools you need. Most of the time free (for softwares), sometimes very cheap for test hardware (for the one you can do yourself), sometimes very expensive like professional spectral analyzer and swr meters.
If you are not ready to spend a lot of time to learn radio technics and experiment, or you can't buy basic test hardware, i advice you to keep things simple and buy ready made antennas / wifi hardware.
Radio is not something simple, it's more like an art.