Okey i see you don't know much abouyt how that works. So im going to explain to you:
First of all there are sockets in your armor. Only armor above lvl 15 has those sockets which are enchantable/imbueable with different abilities/skills (depends on what you like to call it, same thing and result). If you imbued your armor socket with an ability/skill you can't have more then one ability/skill in one socket so which makes it total 5 different skills/abilities as you can see on many in-game screenshots or videos.
I don't believe that will be any sockets in weapons, but if there will be they will only boosts your stats and not give you any skills/abilities since i havent seen 6 icon on gameplay videos.
The skills/abilities that you imbue into your sockets of course have different effects and therefore not all classes can have exactly everything what other classes can have. Also the skills/abilities depend on which armor socket it is, there are specific skills/abilities that can be imbued/enchanted only in helmet or armor or etc... You get the point. And of course different skills are available after different lvls but the first one you will be able to use is at lvl 15 as i mentioned earlier.
Also those the skills/abilities that you imbue/enchant aren't permanent, you can take them out after a battle and change them with other once you have.
Hope this explained few things for you.
