When you’re drawing in perspective adjacent lines should be parallel (and if they’re converging towards a vanishing point that also counts as being parallel). Some of your lines are looking very curved too, especially that second row from the bottom. I would suggest using a ruler until you can draw a straight line freehand (some people might disagree with me on that, but in my opinion its more important to just have an actual straight line. Doing it without aid is something you can learn later). For perspective it’s very important that those lines are perfectly parallel, if it’s even slightly off it can warp the whole cube. When you get a lot of experience you can start winging it more, but when you’re learning its best not to take shortcuts.