Look for angles that go towards one another ever so slightly, as this is key to establishing the box into correct perspective. It helps to give labels to each direction of the box, such as X, Y, and Z, to keep track of which lines need to be converging into the same direction, as I know all the different lines can become confusing when you are first starting out. You got this!

Hey there! I like that you're simplifying the figure into its basic structure. Something you could try out is a general, sweeping curve to first start out your drawing. This can help create an energetic, fluid rhythm in your drawing that the rest of your simplification can follow along with. Also, using CSI line variety (like in the snail and boots project) can also be another tool to bring a more dynamic quality to the drawing. Hope this helps! :)

since i'm not an artist, my best advice is just keep trying and draw more with deliberate practice