You can find here exercise sheets for the Tree Automata Techniques and Applications course taught in MPRI M1 at ENS Paris-Saclay.
Exercise session 1: Recognizable Tree Languages and Finite Tree Automata.
Exercise session 2: Regular expressions.
Exercise session 3: Decision problem, Residuals, Homomorphisms.
Exercise session 4: WSkS.
Exercise session 5: Logics.
You can find the source of the sheets here.