Pot odds are basically how much you have to pay with respect to the pot size.
Let's say there is $500 in the pot, your opponent bets $250. This makes the pot $750 in total, while you have to pau $250 to continue. 750:250=3:1 pot odds. So for every dollar you put in, you can win 3 more. This means you have to win 1 out of 4 times to break even.
That's where pot odds are used for. To calculate if it is a good call or not. Pot odds are a way of calculating how much you can win with respect to how much you have to pay. Later on you can also practice with the pot odds you are giving to opponents, but for now I would focus on the odds your getting. Try to make a routine out of it, every time you're in a hand, calculate the pot odds. It will take time at first but later it will be easier.
Once you have pot odds down, it is time to look at the probability of winning a hand (also sometimes referred to as "poker odds"). But that's for later ^^
Feel free to ask anything if you need some more help. Good luck