Brachylog, 20 bytes
c≡ᵍ∋Ȯ&;I∋₎;J∋₎gȮ∧I;J Outputs [I,J], where I is the row index and J the column index, both 0-indexed.
Stupidely long, but getting indexes in Brachylog is usually very verbose.
###Explanation
Explanation
c Concatenate the Input into a single string ≡ᵍ Group identical characters together ∋Ȯ Ȯ is a list of One element, which is the needle character &;I∋₎ Take the Ith row of the Input ;J∋₎ Take the Jth character of the Ith row gȮ That character, when wrapped in a list, is Ȯ ∧I;J The output is the list [I,J]