I personally have no problems showering immediately before or after practice.
Similarly, I personally have no problems eating immediately after practice.
If I eat a meal, I usually have no problems doing standing practice afterward.
For vigorous movement, I usually wait until I feel comfortable [about an hour].
But everyone is different. If you don’t feel comfortable, listen to your body and wait. If you are not yet so attuned to your body to know, nausea and/or belching will be an indicator that your body is not ready.