What is an easy way to not be sore by the end of the day?

Yesterday was my first day of football in a year, so I'm out of shape. Yesterday all we pretty much did was stay in our stances for about 45 minutes, that made my legs so sore, then we had to run for another 45 minutes. When I woke up this morning I was so sore, I can barely even stand up, move my arms, etc. without getting shocks of pain. What should I do?