That will depend on the school and the style. In some places it only takes a few minutes, others will spend several hours going through all the basics.
It depends were you live.
karate
No reason that you can't, as long as you take appropriate precautions to keep the uniform clean.
The original (made in 1984) is 126 minutes long and the reboot (made in 2010) is 140 minutes long.
it would take 3 or 4 years to get a black belt
No, there is no season for karate. Karate-ka practice all year long.
Yes, Brenda Sung did take Karate. She originaly wanted to join dance classes. But she ended up joining Karate with her Brother, who now no longer takes Karate classes.
No he was a full time in boxing and never did karate.
professionally : how ever it long it takes you to get to 4th dan (takes about three year to go to white to black) each dan could take years to get what karate masters say: 10,000 hours
well everybody can learn karate as long as they can do it and they love it.
A karate instructor is not required to have any academic qualifications.
There are no age limits in karate. People can start their journey at any age.