Think lifting a weight just means moving it up and down? Okay, technically it does. But there are a lot of different ways to approach that moving! Confusing your muscles by trying something different forces them to work harder to adapt.
WEIGHT IS JUST A NUMBER. Muscle weighs more than fat. As you do strength exercises and tone your muscles you will be gaining pounds, but as you do cardio and burn fat you will look like you should be going down on the scale. It's okay if you go up!