Which one is better keyword if I target global auidience?

My website is on football (soccer). I want to target global visitors not only USA visitors.



Should I use the word football permanently instead of soccer? or sometimes should I use the word soccer if it is targeted to the USA visitors like "soccer training center"



Or should I combine like "football (soccer) jersey" ?



I am bit confused, cannot rely on the adwords keyword tool because of football- soccer confusion as football is a completely different game in the USA. Please suggest your advices.

Something doesn't fit together: You ask a beginners keyword question but want to target an extremely competitive field.

I would advice that you forget about this specific keyword for the moment and try to find a low competition niche

These keywords are just examples. I have targeted more specific keywords. Football attracts me a lot that is why I have chosen it.
Low competition niche like?

Use Soccer, because USA is the best online market