For a start you can't just go to Mars whenever you want. Mars should preferably be on the same side of its orbit as the Earth, so as to minimize the distance travelled. Even then it takes seven months to get there, which would expose a human to the long term health effects of space radiation and zero gravity.
So as you can see, the main problem with sending humans to Mars isn't getting there. We've already sent car-sized object to Mars several times. The problem is the health effects of long term space travel, and the extremely harsh conditions on Mars.
Here are Elon Musk's plans for Mars, which are obviously just marketing hype.
Don't believe any hype you hear, we're not sending humans to Mars in the foreseeable future.