I need to do a special effect where a person falls into an open manhole on a sidewalk what software do I need in order to pull this off and when I film it do I need to do anything special?
There's always many ways. Easiest is just to video the man walking up to the manhole (which is covered, obviously), video the same scene without the man, cut the takes together where the man reaches the manhole, mask the manhole cover in your NLE so it looks like a hole. Static is obviously going to be easier.