How does Sorcerer Work?

I want to do a default Durge run, the “intended” Larian approved Durge, but he’s a Storm Sorceror

It’s the only class I’ve never been able to wrap my head around. The whole meta magic and spell slots stuff just confuses me.

Why do that when Wizard, Druid and Warlock are right there?

So pretend I’m an idiot, how does it work?