I've seen way too many people go super hard at the gym and never ever give their body a chance to recuperate - it's essential for growth! You should have at least 2 rest days incorporated into your week. This would look something like the following: one day of no gym at all (no cardio or lifting) and one "active rest day" (here you can do cardio, but no lifting).
What are some ways to help recover?
Sleep
Sleep is huge with recovery. This is the time that your body is healing itself and growing. Lifting causes micro trauma and this forces the muscle to adapt and grow. If you aren't getting adequate sleep, how can you recover and grow? You can't fully and this will end up slowing down your progress.
You should aim to get 7-8 hours of sleep every night. But, quality is just as important as quantity. How can you evaluate this? Do you wake up feeling rested? If so, you are getting quality sleep.
Fueling Your Body
Your body needs the tools to be able to recover and food is crucial to that. What you eat matters and the timing of your meals can be just as important.
Did you know that your should surround a good majority of your carbs around your workout?!
Take Some Time for YOU!!
Our lives are crazy busy and we are constantly on the go, but it is important to take some for you. Utilize this time in whatever manor you see fit, as long as it gives you some moments of peace. Mental exhaustion is a real thing and it can effect how you recover.