No, you don’t have to practice every day, and it’s important you give yourself a break!
Practicing every day doesn’t allow your brain to have the rest that it so desperately needs. Your brain needs time to recuperate and acknowledge the new information it’s been taught. I’ve experienced this myself many times in the past, and although it seems hard to believe, it’s true. I once spent over an hour trying to learn just a couple of bars, and no matter how long I spent I just couldn’t get it right. I stopped playing for a couple of days and when I tried those bars again I could play them much better than before. This was because I was a lot more relaxed and focused, and my mind and approach was fresher.
If you practice something for too long, you may become frustrated, impatient, and stressed. This will of course make it harder for you to improve. By giving yourself a break you allow yourself to relax again, and gain the focus you need to improve. This may be different for each individual, but I find anything from a few hours to a few days allows me to refocus, and gives my brain a chance to catch up and store new information. Sometimes you may only need an hour or so, depending on what you’re learning, but typically something that’s pushing you to your limits requires longer.
For beginners I would advise practice sessions of around 10-20 minutes which should optimise your practice, and around 3-4 days per week. This should then increase as you progress. For example, intermediate players (grades 3-4) may want to consider 30-40 minutes for 3-5 days a week, and advanced players (grades 6-8 and above) anything from 1-2 hours for 4-6 days per week.
I can’t stress enough however that these suggested times above are not to be taken as gospel, and are just to give you an idea of what would typically work for the average person. Everyone is different, and you may need to figure out for yourself what works best for you.
Finally, there are also other considerations. For example, make sure you’ve had something to eat or drink. Keeping hydrated is especially important for your concentration levels. And try to keep yourself shut off from the rest of the world, so there are no distractions. If you can practice at a certain time of the day which ticks all these boxes, then you are on to a winner…