You can jump to the beginning of the previous change with the [ mark by hitting '[ from normal mode. Similarly, you can jump to the end of the previous change with the ] mark by hitting '].

Text that was just pasted is also considered a change. Thus, hitting '[ and '] will jump to the beginning and end, respectively, of the text that was just pasted into the buffer.

See :h '[ and :h '] for more details.