To master Earth Magics you will first need to learn Read and Write and First Aid and then Healing Arts which lets you learn Spell Slots to use with Earth Magic (either healing, necromancy, or both) as well as perform some basic medical diagnostics.

Now you can spend build on Spell Levels. You must have at least as many spells at the immediately lower level as you buy at a given level, and until you have at least four at the next lower level you must have MORE spells at that level.

Thus its valid to have; 2 level 1 spell slots and 1 level 2 slot. OR 3 level 1 and 1 or 2 level 2. But until you have 4 level 1 slots you can not just buy 4 level 2 slots. It ends up looking like a tower with a conical or pyramidal roof on top.

The list of Earth Magic spells and their incants includes one major wound curing spell at each level:

Each level also has a mix of protective, binding and utility spells. And at level 9 the healer can also cast the Death spell "I grant you the Gift of Death".

Making Potions

Earth casters who wish to create interesting items often learn the art of crafting potions which lets them put selected spells they know into a potion bottle . The spell in the potion affects the drinker immediately despite any protections in place. If unconscious someone can "force feed" you a potion. The major limit on potions is that not all spells make good potions and that they can not be mixed in to other things. They are always visibly separate, unlike say Alchemical Elixers.