Sorry no one has answered you yet but I will do that for you now.
You can check either when it is warm or cold. The dipstick can get too hot to where it doesn't measure the level correctly, but that is easily solved by slightly cooling the dipstick. You can check the oil level just a couple of minutes after you turn the car off without any issues because it should be close. I recommend checking it cold that way it is the most accurate. First pull the dipstick out, wipe it off, reinsert it, and then pull it out to check the level.
Troy
You can check either when it is warm or cold. The dipstick can get too hot to where it doesn't measure the level correctly, but that is easily solved by slightly cooling the dipstick. You can check the oil level just a couple of minutes after you turn the car off without any issues because it should be close. I recommend checking it cold that way it is the most accurate. First pull the dipstick out, wipe it off, reinsert it, and then pull it out to check the level.
Troy