You either activate your Familiar first or your hero first.
You are not allowed to mix both activation to perform one action with your hero, then another with your familiar and then one with your hero again.
Familiars (Rulebook, pg. 17)
A hero player may activate each familiar his hero controls once during
his hero turn (either before or after resolving all of his hero’s actions).
Activating a familiar does not require an action, but it may not interrupt
any other action. Essentially, a hero player with a familiar must choose
whether to activate his hero first or his familiar first. Regardless, both may
be activated during his turn.