How do I go to the first search result in a file?

ggn will bring you to the first instance of your search in the file -- the gg brings you the beginning of the file and the n goes to the next match of your pattern.

You can also use gg2n to go to the second instance in the file, or gg42n to go to the forty-second instance. You can similarly use G$N to go to the final match (G brings you to the final line, $ brings you to the end of that line, and N searches backwards), or G$2N to go to the penultimate one.

Obscure Ex commands for the win:

:ij[ump] foo  "jumps to first foo that is not in a comment
:ij[ump]! foo "jumps to first foo, comment or not

See also :il[ist].

Use the gg command to navigate to the beginning of the file.

gg

/foo