Warehouse (yellow enemies) Get enough high strength to challenge the drunk in the bar on the second island. He drops the warehouse key. Go to the warehouse next to your basement apartment. You have to kill all the yellow enemies. Afterwards you get $500 and a strength bonus.
Mobster Tower (black enemies) Fight and beat the two mobsters outside Vinnie’s at night. They drop the mobster tower key. -Go to the mobster tower adjacent to your apartment on the second island. Kill all the mobsters. You get $350, 10 strength, 5 charm and an AK47.
Gangster HQ (red enemies) Get enough strength to challenge and beat the gangsters on the first island near your basement apartment during the morning. They drop the Gangster HQ key. The Gangster HQ is near the pizza shop on the first island. Kill all the enemies. You get $625, 15 strength and a double barreled shotgun.