Well, it all started when Tony was kidnapped and forced to build weapons. He then built a suit to escape and decided to use his tech for good, becoming Iron Man.
Tony Stark became Iron Man after being kidnapped by terrorists. While captive, he was forced to build a weapon. Instead, he created a suit of armor to escape. This was the first version of the Iron Man suit.
Tony Stark became Iron Man when he was captured by terrorists. He was forced to build a weapon for them but instead, using his brilliant mind and the limited resources available in the cave where he was held, he built a suit of armor to escape. This was the first prototype of the Iron Man suit.
First, you need to understand Tony Stark's character really well. Read the comics, watch the movies. Then, create an interesting original character (OC). Give your OC a unique backstory, personality traits that can interact well with Tony Stark's. Also, come up with a good plot. It could be something like your OC helping Tony Stark in a new technological project or facing a common enemy together.
In Iron Man 1, Tony starts as a carefree and self - centered billionaire. By the end, he begins to see the potential of using his technology for good. In Iron Man 2, he becomes more aware of the implications of his actions and the need to protect his technology. In Iron Man 3, he matures further, dealing with his trauma and becoming more selfless.
In the comics, Tony Stark's age can vary depending on the specific storyline and continuity. But generally, he's depicted as an adult in his 40s or 50s.