Vortex Sound Research

I'm very new to synthesizers. I use a midi controller with Dexed. A friend of mine has an instrumental band and he's invited me to play. I've watched a few videos on playing live with a controller but I just want to confirm with you guys. From what I understand, I need an interface for my laptop which is then plugged into a DI Box. Then the DI box can go into either a PA or an amp? Please tell me what I need to do if I'm wrong.