Nightclubs in GTA Online are businesses included in the game as a part of the After Hours update. Any of the ten clubs can be purchased at the Maze Bank Foreclosures website.
To complete this objective, you need GTA$5000 and grenades or another weapon which allows you to blow up cars quickly.
Find a parking lot with at least six cars on it. Then call Lester, select the “Cops Turn Blind Eye” option, and start blowing up cars. Usually, it’s enough to blow up six vehicles to complete this objective. But if it wasn’t, continue to blow up vehicles and kill NPCs until the message about the completion of the objective appears.