Improve the bracketed part of the sentence.
Shouts of the crowd cheering the home team now (stuff) the air.

* Stuff means to force or cram something into a small space, which is improper when describing sound in an open space like an arena.
Fill is the standard and correct word to describe sound pervading or permeating an atmosphere ("shouts fill the air").

Occupy refers to residing or taking up physical space or time.

Infest means to be present in large numbers so as to cause damage or disease (used for pests or weeds).