1988 Ford Ranger Accelerator Pump?

My truck is still having a hard time starting on a cold start after changing out the fuel pump so I made a video of what was going on, because it only has a problem during the first start, after that I can start it all day long without a hiccup. I was told by the main mechanic that I go to, it most likely is something called an Accelerator Pump, somewhere in or around the carburetor. This means its mostly likely over my ability as I have been told DO NOT TOUCH THE CARBURETOR!!!! HAHA Even if that is true I would still like to know more about this part, where it is located, and why it seems to cause the problems that it does.
I’m not sure how to post the video or I would.