All have equal chances to get infected since parasites swim in the water and in the tank you are limited by the volume of water. If its not visible on the skin, then its in the gills (assuming the fish is infected in the first place).
Usually tangs are considered ich magnets since they have thin slime coat so it appears all over the fish
Clownfish are brook magnets and usually brook is called clownfish disease.
Damsels in general are Uronema magnets and usually they get infected with it more than any other species
and so on..
You need to perform proper quarantine to avoid disease.
You need to focus on what fish requires strict parameters and are considered sensitive and what fish are considered hardy, what can survive in your tank and what is considered large for the tank, etc..
If you are beginner to reef tanks, then start with easy, hardy fish like clownfish, damsels, some wrasse, gobies, bennies, basalt, etc. avoid some fish that are more sensitive like some of these species: tangs, angels, butterfly, anthias, ...
There are many websites available that tells you the fish requirement and how easy or hard it is to take care of.
Again, make sure you quarantine properly and you should not find any disease in the tank, also if you buy them from LFS, observe them for couple of days before buying them to ensure they dont develop any diseases that you are not ready for.
Best of luck and welcome to reef2reef