Я немного говорю по-испански и по-немецки. -- I speak a little Spanish and German.
The phrase "Я мало говорю по-испански" means that you don't speak too much, don't practice too much, don't spend too much time speaking Spanish.
As for the second part of your question, if the noun follows "мало" (which is not your case) it takes the genitive form: мало времени, мало денег, мало проблем etc.