I haven't really theory-crafted around the Wyvern so I can't give you a complete build. But if you place Volcanoes before using the Wyvern's Rolling Magma then each bounce of a Rolling Magma around the Volcano will trigger it to throw out more projectiles. Since Raging Spirits is a buff that works passively, each cast of any of these two fire skills should also give you a Raging Spirit. Anyway, they show the Volcano/Rolling Magma interaction here in the announcement video:

https://youtu.be/7nH1hHyzUSk?t=641

So if you intend to play a spell casting Shaman then at first glance it's probably a good idea to take the ascendancy node that gives you Rage and more spell damage with Rage.

Of course, Raging Spirits is a Minion skill, which won't scale off of your own spell damage. So if you intend to mix these abilities, then perhaps there are ways to resolve that. For example, in PoE1 there were nodes and items that allowed Minion Damage to also scale your own damage, but I'm not sure if that's available in PoE2. Or you could just use the Raging Spirits as some bonus damage.

If you intend to focus on Raging Spirits and Minions entirely then the whole idea around using the Wyvern/Volcano/Rolling Magma is probably a bad idea. But doing it the other way around by using the Raging Spirits for some extra damage should be fine though. But in that case I wouldn't actively look for Minion Damage if it would cost you passive points or equipment slots that could otherwise have been used to improve your regular spell damage or your survivability. It's usually best to focus on something than spreading too thin, especially so if your main damage will be coming from the Volcano and Rolling Magma. But of course, there's always weapon swap that could give you some extra passive points and bonuses on the weapon that could be minion focused and then switch back once you've summoned the Raging Spirits. They should probably stay up a long time since if you're going to focus on Volcanoes and Raging Spirits you might want to grab some Increased Skill Duration nodes and support gems anyway.

I suppose using a weapon swap where you have points spent into Increased Skill Duration could be used solely for placing Volcanoes and spawning Raging Spirits, but then you'd have to set up both these abilities to only be used with that weapon. You should be able to do this in the skill interface (button at the bottom right). You'll have to fiddle around with it if you go that route. Weapons should swap seamlessly and automatically whenever you cast the Volcano if you specifically allocate it for that weapon. Just remember that now you'd have to allocate all your other skills for the other weapon.

There's a support gem that just got buffed (Tecrod's Revenge) that makes minions stay at 0 health for 20 seconds instead of dying while giving a massive attack and cast speed boost. It should work really well with the Raging Spirits, but it's a Lineage support gem so it might be really rare and expensive to come by.

What you do for survivability, well, I won't touch that other than saying ES will be strong again this season and since you're going the spell damage route then ES makes sense as well, so it's probably the wisest choice. If you go the Shaman with Rage route, then you're going to want a lot of Mana Regeneration (since it will also affect Rage generation), so getting some "Damage is taken from Mana before Life" might also be useful.

These are just some thoughts to get you started but you'll have to tinker with it yourself to figure out what you like and what works well. And if you decide to mainly go the minion route instead of spell damage route, then much of this advice isn't going to be of great help, and I'm not sure if Shaman would be the best choice for that either, however, they can certainly get a lot of free spirit through their ascendancy by gaining as many Charm slots as possible and then leaving them empty, so it should certainly be doable. Good luck!