This is one of the most common questions someone asks when they are starting a workout program. In general I like to tell people that 4-5 days per week is a good amount. But this all depends on what type of training you are doing.
Natural lifters in general respond much better to high frequency compared to high volume. So the more times per week you can hit your muscles the better. Just make sure the volume in your workout isn’t too high. You can check out my article on training splits here.