Odometry is a way of tracking your robot’s position on the field accurately. It uses “dead wheels” that are on the ground and are not powered by a motor, and shaft encoders to track the distance those wheels move. All of the math is to convert from the movement of the three tracking wheels to a x and y position on the field. It is a more advanced algorithm used in Vex, and it’s probably overkill for a new team, so I wouldn’t do it to gain a competitive edge, but if you’re still interested in learning I recommend the BLRS article linked above for the math, and the youtube video linked above for understanding it. It can definitely be implemented in Vex C++, but it will be a lot of math and I don’t recommend doing it if you don’t have a solid understanding of trig functions.