What was the first company that came up with the business plan of taking tourists to space? In which year was the company launched or the outline of the business plan known to public? What was the first spaceflight company to have its own launch vehicle?
Between 1968 and 1971, Pan Am issued over 93,000 “First Moon Flights” Club cards to space enthusiasts eager to make a reservation for the first commercial flight to the Moon. Issued at no cost, the membership cards were numbered according to priority. The Club originated from a waiting list that is said to have started in 1964, when Gerhard Pistor, an Austrian journalist, went to a Viennese travel agency requesting a flight to the Moon. The agency forwarded his request to Pan Am, which accepted the reservation two weeks later and replied that the first flight was expected to depart in 2000.
They seem to have been content to take reservations without investing in a vehicle.
The Russian space agency has long been amenable to paying passengers. Initially these were all professionals (through the Intercosmos program), but from 2001, Space Adventures sold seats on Soyuz flights to tourists.
In 1995, the X-prize was announced (later renamed to Ansari X-prize), awarding $10M:
for the first non-government organization to launch a reusable manned spacecraft into space twice within two weeks.
This served as a catalyst. 26 companies competed, with Scaled Composites and their Spaceship One becoming the winner in 2004.
A few notables among spaceflight companies:
Bigelow was founded in 1998. Its long-term goal is a hotel in space.
In 2000, Blue Origin was founded. They have made 4 test flights with their intended tourist vehicle so far, first flight was in 2015.
In 2004, Virgin Galactic was founded, they partnered with Scaled Composites to develop Spaceship One into a commercial venture. First flight of Spaceship Two was in 2013. In 2014 they suffered a crash with one fatality while testing their intended tourist vehicle (Spaceship Two).
SpaceX was founded in 2002, with a goal of transporting people to Mars. They haven't made a manned flight yet.
So, 'first to have its own launch vehicle' is Virgin Galactic. Launch year of the first company will be around 2000. Most of the Ansari X-prize competitors have folded and some weren't in a position to win to begin with, so I'm not sure how seriously to take all of them.