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.
The friends' reactions would depend on their own personalities and relationships with Rip and Sara. Nate might be the one to crack jokes at first to ease the tension but then become very serious about making sure they have all the resources they need. Amaya could see it as a sign of new life and growth in their group, and would be eager to help Sara adapt to her changing body and new role as a mother - to - be. And Captain Cold, if he were still around, might be a bit cynical but still secretly hope for the best for them.
One possible plot could be that they discover the pregnancy unexpectedly. Maybe they were on a mission and Sara starts to feel unwell. They initially think it's something related to a recent encounter with a strange alien or time - traveling anomaly. Rip is both excited and terrified as he realizes the responsibilities that come with having a child in their dangerous line of work. Sara, on the other hand, is more practical and starts making plans for their safety and how to continue their heroic deeds while pregnant.
The protagonist of Pokemon Yellow is an obvious potential ally. They are on their own journey to become a Pokemon master and could easily team up with Lance. Another could be Professor Oak. He has a vast knowledge of Pokemon and could provide valuable information and resources to Lance. Also, the Gym Leaders in the Pokemon Yellow world could be allies. They are all skilled trainers in their own right and could join forces with Lance when facing a common threat, like an evil team trying to disrupt the Pokemon League.
Well, the 'dragon aura' in Monster Hunter Stories could be a manifestation of a dragon's strength. Maybe it's related to their elemental powers, like a fire - breathing dragon having a 'dragon aura' that is hot and fiery. It could also be a sign of their dominance in the game's ecosystem. For example, a more powerful dragon with a stronger 'dragon aura' might be harder to defeat or might have a greater influence on the surrounding areas in the game world.
I'm not sure if 'Dragon Field Hunter' is a popular light novel as it might be relatively unknown or a niche title. There are so many light novels out there that it's hard to say without more information about its sales, fan following, or critical acclaim.