Some folks, at some time, decided that there were six continents: Africa, Asia, Australasia, Europe, North America, and South America.
A bit later "they" added Antartica.
It all seems to be a bit arbitrary to me.
Eurasia is one land mass.
So are the Americas.
Australia is an island. So by what canon is New Zealand included in the continent of Australasia?
Similarly, those island(s) which include England, Scotland and Wales, and those island(s) which include Ireland are counted as part of the continent of Europe.
But of course, this designation of lands masses as "continents" is a geographical and political convenience.
In terms of that convenience I have visited (or lived in Europe), Asia (in which case refer to a visit to Lebanon which few folks think of as an Asian country); Africa; North America; and South America.
Next comes Australia. God willing I will visit that continent later this year.
I am a lucky to have been able to visit in the Americas, Asia, Europe and Africa, and to anticipate a visit to Australia.
More than lucky: - I am blessed.
I am blessed to have been with so many good people, in so many part of God's world. Those people have taught me so much