I am not great artist. I am much better at writing code than drawing, sculpting, sketching, painting, modeling, you name it.
So, whenever I find something that helps me out with game art, either because it is free assets that help me get started or tools that help me generate art that looks half decent, I try to share it.
Fortunately there is an absolute LEGEND named Kenney who has created literally thousands of assets for people to use for FREE, no strings attached as his website says.
He provides assets for all kinds of games. Platformers, top down shooters, RTS, dungeon crawlers, city builders, racing games, pirate games, you name it. I especially like the 2D Generic Items.
You can find them on his website.
He also has a couple of art creation tools for sale (at extremely reasonable prices) to help you create your own custom 2D or 3D assets.
If you are struggling with game art or just want some placeholders as you get started on a project, try it out.
Keep getting wiser, stronger, and better.