I am having trouble to get the engine to idle.

If this engine has a 4 bbl cab, wth the engine off open the secondary air flaps 9on top of carb, and use a screwdriver to tap on the lower secondary throttle plates to make the close fully. They sometimes stick.

Also [engine off] open the primary air flap (top front of carb) and the open the throttle for a second or two. This will allow the choke idle cam to fall down to its disengaged position. (The choke engages when the primary air flap is close or partially closed, thereby increasing idle speed)