I don't know what country you are in, but most missionaries are either Christian or Muslim. There are Christians of all kinds-- Catholics, Lutherans, Mormons, Baptists, etc-- who send their members to various countries. Muslims have also sent out people to teach about Islam and spread the Muslim faith to other countries.
Missionaries usually are there to teach you about their religion, in the hope that you will convert to it. Some missionaries also set up houses of worship (whether churches or mosques), so that you will have a place to practice your new faith. Missionaries believe that they are supposed to spread their faith; for example, Christian missionaries believe Jesus himself instructed them to do so. Most missionaries sincerely believe their religion is the only one that has the truth, so they want to share it with those who may not know much about it.
Some religions do not send out missionaries. There are very few Buddhist missionaries these days (although there were some in the generation after the Buddha died; those missionaries spread Buddhism to a number of Asian countries). And Jews do not send out missionaries at all, because Jews do not believe they have the only true religion, nor do they believe they are supposed to actively try to convert people. As with Buddhism, centuries ago, some Jews did send out people to teach about Judaism, but this is not a part of modern Jewish practice. (People can and do convert to religions like Buddhism and Judaism. But these faiths do not have an organized group of people who go out to persuade you to join their religion.)
Thus, given that the majority of today's missionaries are Christian or Muslim, the chances are good that the missionaries you met were from some denomination of Christianity, or possibly from Islam.
In what country?
Saint Patrick did not 'start' any country. He did go to Ireland as a missionary but did not found that country.
A missionary.
'Missionaries' is the plural of missionary. A missionary is a person who is sent on a mission, especially one sent to do religious or charitable work in a territory or foreign country.
The Island of Cyprus (Acts 13:4-12)
St. Patrick, called the Apostle to Ireland, was the original missionary to that country. Through his hard work, the majority of the pagan Druids became Christians.
a missionary
That person would be called a missionary. The work would be called missions.
Afghanistan . However, this was before the west invasion of the country. The situation is not clear now after many Christian missionary activities in the country.
What country?
The Avispa Country Club is to be found at the southern end of San Fierro, next to Missionary Hill.
country from which tourists visit jamaica