The story has a few "siege" encounters yeah, the expansion also has them. They're nice to do once but they're fairly horrible to farm which made Zorah one of the worst monsters in the end. There's also the larger multiplayer encounters in endgame that have a bunch of phases and mechanics, in the original it was Kulve Taroth and in Iceborne is Safijiva, they use a multi group meta progression system(each groups contributes to a bigger goal and when the bigger goal is reached every group is rewarded with stuff), these are pretty fun overall although I wasn't a fan of KT after a while due to the ultra RNG nature of rewards.
Insect Glaive is a pretty nice weapon, it's just kinda annoying to have to collect essences. Which btw if you're new, you're doing right?
You use the left trigger+button(I think haven't played IG in a while) to shoot the insect at a monster part and it gets a colored extract then you recall it with trigger+other button to get the extract.
Generally head/front legs would get you red which gives more damage and an improved moveset(a must have since you get additional strong moves on basically everything), hitting the wings or sometimes legs will give white which gives improved movement speed and hitting chest/sometimes back legs will give orange, which gives increases defenses and reduced staggers from some stuff and when they're combined they give more powerful effects. White+red is generally the basic one you need to do hunts properly but adding orange for all 3 gives you minor earplugs and more damage and defense increase which is great, although it can't be refreshed until it drops.
Also if you got confused by the crafting stuff, maybe you didn't notice you can also upgrade your Kinsects, and you definitely should. Focus on the ones that have max speed, as speed is the one important stat to make sure they reliably hit the parts you want extracts from.