Can I use expansions with the second edition without owning the first edition?
Even if you don't have the first edition core game, you will still be able to use "Call of the Wild" and "Forbidden Alchemy" to expand your second edition.

(However, the "Suppressed Memories" expansion for second edition will probably be a better choice in financial terms.
It contains all the components from "Call of the Wild" and "Forbidden Alchemy" that are used by second edition)