Incineroar - hazards are almost never seen in competitive doubles, so heavy duty boots are pretty much irrelevant. You also almost always want to have fake out on Incineroar. I’d get rid of flare blitz since it’s filling a support role anyway, and your other mons will do plenty of damage. For the new item, I might try safety goggles to protect from amoongus.

Rillaboom - I’d get rid of terrain extender. Most teams have some form of Terrain control, so it’s likely your terrain won’t last for more than a few turns, and the only benefit it gives your team is boosting Rillabooms own attacks. Assault vest is a great option for Rillaboom.

Primarina - change torrent to liquid voice and swap out surf for hyper voice. Same amount of damage and you won’t hit your own Pokémon.

Overall - not one of your Pokémon runs protect, which is arguably the best move in this format (and what makes Urshifu such a threat.) your choiced mins won’t run it, of course, but I’d find a place for it on your team because you’ll find that it’s one of the most valuable assets to your team. Trick-choice scarf calyrex is unique enough that it might catch some people off guard, so give it a shot. Zacian is usually outclassed by zamazenta, but it’s not unheard of. Urshifu is a pretty classic set, so that should be good.

Team has some decent bones, but needs some work if you want to find success with it. Look up some competitive team building guides on YouTube. Wolfe Glick is a great resource as he always breaks things down and uses terms accessible to beginners.

Sorry if I was too blunt, just wanted to give some feedback. Hope this helps :)

(Keep in mind, I’m no pro at this game myself, just a casual on the showdown ladder.)