In an example in class we were asked to determine the ground state total orbital angular moment and total spin angular momentum quantum numbers $\textbf{L}$ and $\textbf{S}$ of Nitrogen with electron configuration
$$N:[\mathrm{He}]\,2s^22p^3$$
We are told to used Hund's rules which were given as the following.
Find the maximum $\space M_S$ consistent with the Pauli Exclusion Principle. Set $S=M_s$
For that$\space M_S$, find the maximum $M_l$. Set $L=M_l$
It was then presented that the result is as follows.
$$\max(M_s)=\frac{3}{2}\implies S = \frac{3}{2}$$
$$\max(M_l)=0\implies L = 0$$
$$\therefore S = \frac{3}{2}\space \text{and} \space L = 0$$
I am trying to do homework problems similar to this and can not figure out how they reasoned $L = 0$ and was hoping to gain some clarification if at all possible.When moving to atoms with partially filled $\space f$ and $\space d$ orbitals I don't know where to start and I think it is because I am not sure how they approached this problem. Any help clarifying this process would be much appreciated.