after eating, how long should I wait to begin the exercises?

I have a slightly different answer as the others. Since you don’t state that you’ll be eating a meal, having a light snack consisting of a carb and protein an hour prior to working out will help to fuel a more intensive workout. Especially if working out in the morning, having something light to eat prior to a workout is a must as you’ve been fasting while sleeping.

However if you’ve just eaten a large meal, 2-3 hours is the ideal to aid in digestion.