Iron Man and Howard Stark would likely start with a bit of shock. Howard might be amazed at the technology Tony has created, and Tony would be in awe of seeing his father alive (if it's that kind of scenario). They'd probably exchange some witty remarks, with Howard being a bit more old - fashioned in his speech. Then they'd start discussing technology, with Howard offering some of his classic insights and Tony showing off his modern advancements.
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.
There's no official indication in the main Marvel canon that Howard Stark reads Iron Man fanfiction. Howard was a brilliant inventor and businessman, mainly focused on his scientific and entrepreneurial pursuits. Fanfiction is a modern and often fan - created concept that might not have been part of his world view. However, in some alternate universes or fan - speculations, it could be possible, but still not a common or established idea.
There's also 'Howard's Shadow'. This fanfic focuses on Tony's struggle to live up to his father's reputation. It has a lot of flashbacks to Howard Stark's days, which gives great context to the Iron Man story. It's really interesting to see how Tony navigates the challenges while being in his father's shadow.
In many fanfictions, Howard Stark's early tech designs are a major influence. For example, Tony might find an old blueprint of Howard's that gives him an idea for a new Iron Man upgrade.
He might be confused at first. Howard Stark was from a different era and fanfiction was not a thing during his time. But if he understood the concept, he might be flattered that his son's story had inspired so much creativity among the fans. He could also be critical as he was a perfectionist, and might not like some of the liberties taken in the fan - created stories.
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.