If you've never taken a pistol related course before and don't wanna fork out for the BB right now you might want to consider taking the holster course at TSE first. It worked out really well for me - all I needed was a holster and 250 rounds of ammo, on top of the $50 for "tuition".
After getting equipped with the holster for that course all I needed was a couple mags for the BB, and I'm much more confident with the pistol now.