  We present a reconstruction in early data of the semileptonic decay $B^+ \to
\pi^0 \ell^+ \nu_\ell$, and first results of a reconstruction of the decays
$B^+ \to \rho^0 \ell^+ \nu_\ell$ and $B^0 \to \rho^- \ell^+ \nu_\ell$ in a
sample corresponding to 62.8 fb$^{-1}$ of Belle II data using hadronic
$B$-tagging via the full-event-interpretation algorithm. We determine the total
branching fractions via fits to the distribution of the square of the missing
mass, and find $\mathcal{B}(B^+ \to \pi^0 \ell^+ \nu_\ell)$ = (8.29 $\pm$
1.99(stat) $\pm$ 0.46(syst)) $\times 10^{-5}$. We obtain $95\%$ CL upper limits
on the branching fractions with $\mathcal{B}(B^0 \to \rho^- \ell^+ \nu_\ell) <
3.37 \times 10^{-4}$ and $\mathcal{B}(B^+ \to \rho^0 \ell^+ \nu_\ell) < 19.7
\times 10^{-5}$. We also obtain an updated branching fraction for the $B^0 \to
\pi^- \ell^+ \nu_\ell$ decay, $\mathcal{B}(B^0 \to \pi^- \ell^+ \nu_\ell)$ =
(1.47 $\pm$ 0.29(stat) $\pm$ 0.05(syst)) $\times 10^{-4}$, based on the sum of
the partial branching fractions in three bins of the squared momentum transfer
to the leptonic system.
