Inserting at the end of a line in VIM
Solution 1:
Use A command instead of i. The command appends text at the end of the line. See :help A.
In normal mode press A (uppercase). Vim will be switched to insert mode, and the cursor will be moved to the end of the current line ready for input.
Solution 2:
The $ positions you at the end of line.
Then, to enter insert mode AFTER the end of line, press a.
So, simply typing $a while in command mode will do what you are asking.