You can try completing certain quests or participating in specific events related to it. Sometimes, rare drops from monsters might also give you a chance to obtain it.
One good order could be starting with the Tutorial Island quests as they introduce the basic mechanics. Then move on to the Lumbridge quests which are relatively easy and build a foundation. After that, quests like the Vampire Slayer quest can be a good next step as it has an interesting story and unlocks some useful items and areas.
Naruto would probably be super excited about the Ironman concept. He'd be constantly thinking of ways to use Ironman's gadgets in his ninja world. Yugito might be more reserved but interested. She could help Naruto see how to adapt Ironman's ideas to fit the ninja culture better. For example, making the Ironman suit more stealthy like a ninja.
One great Ironman story is about John MacLean. He was a paraplegic athlete who completed an Ironman. His determination against all odds was truly inspiring. He trained hard and overcame physical limitations to cross that finish line. It shows that the Ironman is not just about physical strength but also mental fortitude.