Pull ups without a pull up bar! I've been playing with this exercise for months. It's perfect to help you get your first pull up. All you need is a Smith machine and a straight bar. Start out with a high bar. Simply grab hold of the bar with your feet on the ground. Then pull your chest toward the bar while keeping your body in a fairly straight line.
Once you are able to do that, you can make this harder by reducing the height of the bar. I generally aim to do 3 sets of 8 reps.
To be clear, this obviously doesn't have to replace other back and arm exercises like the lat pull.
By all means, use both if you like. There are many roads to achieving your very first pull up!
Pull ups are a great exercise that everyone should be doing. If you can't do a pull up, work your way up so that you can eventually bang out your first one. And even if you're good at them, Australian pull ups are great ways to get in more pulling volume.
Have a beautiful day!