You'll find absolute value absolutely straightforward--it is just the "distance from zero". If you have a positive number, it is its own absolute value. If you have a negative number, just make it positive to get the absolute value. As you see as you develop mathematically, this idea will eventually extended to more contexts and dimensions, so super important that you understand this core concept now. Common Core Standards: 6.NS.C.7, 6.NS.C.7c, 6.NS.C.7d
Add and subtract negative numbers using a number line. It's the 7th grade mathematics shuffle: "Slide to the left for a negative value, and slide to the right for a positive value." Be careful, though. Which way do you move if you are subtracting a negative number? The answer awaits!