You are not always born with it, but most abilities are to help the person to understand the thugs around them. Remember with every ability there is a repercussion involved. Like with me, I have future sight, I saw my own funeral at 3. The vision was when I was 17, and it did alot of damage to me, so idk why someone would ask for that, but at the same rate, the ability helped me alot, though it is for the most part gone as I do my nurture it well.
You can't create an ability. I don't understand where you got that idea in the first place.
Everyone has 'abilities'. Though, some are more open than others. If you want to 'gain' an 'ability' then practice it. If you want to be able to see/sense/talk to etc spirits then open yourself up and practice it.
Everyone has the ability to do these things just not everyone wants to actually do the work that it takes to 'awaken' them or remove themselves from the bad generalization that you have to be born with an 'ability'.