Did Great Britain first use the incarceration of enemy civilians (known has concentration camps) ?

Yes , the first instances of the collective incarceration of enemy civilians has a punishment and to deny their participation in keeping the enemy supplied was during the BOER war, 1899 1903 . The Boer people where of Dutch decent and their home land was known has the orange free state. which is situated in what is know known has south Africa. The British fought wars with Zulus and won, then set about claiming the whole of free state which caused the war with the Boers, The Boers fought a gruella type war which caused many casualties to the British army. In an attempt to control the Boers the British instigated the collection of civilians into camps (now understood to be concentration camps) which stopped the civilians from supplying food shelter and munitions to the mobile Boer fighters. The collection of civilians into camps brought about mass death due to disease malnutrition and ill treatment.

No that would be the Russians. The Polish historian Władysław Konopczyński used the term concentration camps when describing events in Poland during the Bar Confederation rebellion (1768–1772), when the Russian Empire established three prisoner camps for Polish captives awaiting deportation to Siberia.

The English term originated in the reconcentrados (reconcentration camps) set up by the Spanish military in Cuba during the Ten Years' War (1868–1878), Cuban War for Independence (1895–1898), and by the United States during the Philippine–American War (1899–1902).

The term concentration camp saw wider use during the Second Boer War (1899–1902), when the British operated such camps in South Africa for interning Boers. They built 45 tented camps for Boer internees and 64 for black Africans.

During the Boer War.

Yes - during the Boar War in Africa. Probably most of the evils of Nazism were learned from the British Empire. The Germans seemed to be especially good at mass murder on their own though - nobody murders like a German unless it's a Russian.

No, the Spanish did in the Cuban revolts of the 1890's.

Yes, during the Boar war.