It's easy to mess up we all do it just some lie about it. But if you fallow so simple rules you going to still have a usable mirocontroller in the end.
Never put power on till you are 100% sure you have the power lines right that's number one
and two always check the wiring a few times always.
Three always limit the power to a pin to big of a resistor not going to hurt to small and you'll see smoke.