Simplified answer is 24-72 hours.
Not so simple answer is it depends.
One of the things that makes fitness so complicated is that there are so many things that just depend. There aren't a lot of hard fast rules in the fitness world. In fact, at the moment I can only think of two really general ones. Training is one of those things that is both an art and a science. The art of fitness is how one applies the science. One of those arts is workout frequency. For the beginner, when your goal is to accumulate 150 active minutes a week, the frequency is less important. In fact, low intensity exercise is a perfect example of a workout that should be done everyday! When the workout is more intense and focused on strength or power time between training becomes more important. Regardless of your goals or type of workout maintaining progress is the key. If you allow too much time between your workouts you won't build strength. In fact, if you go too long between workouts you will start to lose your hard earned strength. This is one of those hard fast rules of fitness. If you don't use it you will lose it! Strength is built through hard work, yet lost through neglect. That is where a 72 hour rule is a great rule of thumb. Don't go more than 72 hours between workouts! Sure life gets busy sometimes. Give yourself grace for those busy days. But if it has been more than 2 days since your last workout find a way to fit that workout in!
Review: 150 minutes per week is your big goal for the first 6 weeks
Record your sessions! Actually write it down.
No more than 72 hours between workouts
Stay active and have fun
-Anna