Qnet and Munet both accept one parameter, so these lines of code will raise the error:
q_target(s_prime,mu_target(s_prime)) # q_target gets two inputs
q_loss =  F.smooth_l1_loss(q(s,a), td_target.detach()) # q gets two inputs
mu_loss = -q(s,mu(s)).mean() # q gets two inputs

You might want to add the second argument to Qnet.forward or just pass the expected a argument.