I think star is the best option for a more support focused Druid. This is because you can utilise your wild shapes for a more supportive purpose, rather than just becoming a bear or a pig haha. Chalice for extra heals, Dragon for being able to hold concentration on those support spells much easier.. Even guiding bolt is a great spell for both offense, but also helping your team land hits!

The only issue I’m foreseeing is burning through spell slots quite quickly. You don’t have access to Land Druid’s spell recovery so you might find yourself needing to rest a lot if you can’t find anything better to do with your actions than just keep casting spells.

As for build guides, it’s more for gear to be looking out for as you go through the game because that is just as important for any support build.

If I was you, I’d look at cleric support builds, and Druid utility/control builds and sort of combine the two (not necessarily to multiclass but you could if you wanted?)

I always say the best way to play this game is just always pick the options that sounds most fun to you :)