Hey there! Iron is definitely a Lewis Acid because it fits the definition as a species that accepts an electron pair (i.e., an electrophile) and will have vacant orbitals.
Here is a comprehensive breakdown of some other scenarios where we could classify a compound as a Lewis Acid:
Now I'm not quite sure that Iron would fit the definition of a bronsted Acid in a common scenario. It would have to have a proton to donate.
If you would give me more context I can give you a more direct answer! However to distinguish between the two you should use other compounds such as Carboxylic Acid or Water which can be both a Lewis and Bronsted Acid.
I hope this helped!