The Belle II experiment offers an ideal environment to study the spectroscopy and decays of quarkonium states. We present several analyses of the data collected by the Belle II experiment at the SuperKEKB facility. Key highlights include the measurement of the cross sections for various processes around the $\Upsilon(10753)$, namely $e^+e^- \to \pi^+\pi^-\Upsilon(nS)$, $e^+e^- \to \omega / (\pi^+\pi^-\pi^0)_{\text{non-}\omega}\chi_{bJ}(1P)$, and $e^+e^- \to \omega \chi_{b0}$, $\omega \eta_{b}(1S)$, the energy dependence of the $e^+e^- \to B\bar{B}, B\bar{B}^*, B^*\bar{B}^*$ cross section and a precision measurement of the B meson mass differences. Prospects for future spectroscopy studies at Belle II are also discussed.