Welcome to Stock, where balance doesn't exist and physics are optional!
Rule 1 of Stock: never change your bot's armor. If you never click on the armor tab at all, you get Double-Strength Aluminum (commonly called DSA), which is just what the name implies. It's stronger and lighter than Steel armor, so there's no reason not to use it.
Rule 2 of Stock: the only wheels worth using are shiny hubs (they're by far the lightest) and occasionally rubber wheels (they're slightly smaller, so they help bots that need incredibly small ground clearance). If you make your chassis five "clicks" high (from the page where you decide your chassis height, put the slider all the way at the bottom, then slowly move it up until you've seen it click 5 times), you can use HP-Ztek motors for drive and be invertible with shiny hub wheels.
Rule 3 of Stock: the only weapons worth using are razors, iron spikes, maces, and sometimes bear claws. Everything else is worthless.
You also need to build to the weight limit. By the way, the default Stock AI is terrible, so grab an AI pack if you want your testing to mean anything. Good luck!
If someone else who is better than me disagrees with one of these points, though, probably go with whatever they say.
