Generally when you start editing a file whether as a new Vim session (
vim file.txt) or in an existing Vim session (
:e file.txt), your cursor will
be positioned at the beginning of the file.
You can start editing a file with the cursor positioned at the end of a file
using an edit command -- include
+ with no line number. This may be
useful for a large file or even if you just know that you'll be adding
content directly to the bottom of the file.
If you are starting a new Vim session:
$ vim + file.txt
or if you are already in a Vim session:
:e + file.txt
man vim or
:h +cmd for more details.