Elemental spirits are part of nature, so are plant spirits and animal spirits.
Elements are part of nature − the building blocks that nature is made out of.
D&D tends to associate "nature spirits" with Fey.
However, most "nature beings" are elementals: river, mountain, rain, lightning, wind, sunlight, and so on, and trees.
This suggests that nature beings arent Fey. Rather, they are Elemental.
Moreover, nature beings arent "spirits", per se. The nature beings are physical objects, the actual river itself, the sunlight itself, the wind itself, the mountain itself, and so on.
These Elementals are nature, but they feel different from Humanoid and Beast that are also part of nature.
Doesn't sound like a druid to me.
The Bard has Mind themes and Life themes (Animals, Shapeshifting, Healing, etcetera).
The Druid has Elemental themes and Life themes.
A Druid character concept can specialize in specific tropes and themes.
When I portray reallife alchemists and alchemical traditions, the Druid tends to be the best class to model them. The Druid can represent both Hellenistic alchemists and Daoist alchemists.