The expert contractor explained the quality and life expectancy of your work will benefit from the right tools. We recommend a Bates brand set for about $20 on Amazon.
Next, add your paper tape and use the same knife to embed it, spreading thinly and press out any air bubbles. After the mud has dried overnight, sand the mud flat.
Once the 2nd and final coat is dry, you'll need to sand the surface until there are no raised edges or seams detectable using your sanding sponge and pole sander.