I wake up at 5. I eat my breakfast at 8. So what do I do in that 3 hrs gap

Do some mind freshening activities like yoga, reading a book, painting or doing any such hobbies etc, or just take a walk outside

First, you can drink water, go to the bathroom, brush your teeth, wash your face, do your skincare routine (even if its just applying a moisturizer and sunscreen), do your hair, meditate/pray, do some form of light physical activity (stretching/cardio/strength training), read a book (novel/self-help or even an article on a topic that personally interests you even if its unrelated to your field) while drinking a drink you enjoy (i’d suggest you avoid coffee 1:30-2:00 hrs after waking up and also on an empty stomach, it’s better to delay coffee until after breakfast), start working/studying the most difficult/important topic as this is the time you’re most focused, although i’d say if you’re a bit unmotivated that day to start, start with something you like or something thats easy/quick so you feel like you’ve acheived something early on and get in the mood of working).
Of course feel free to adjust this, skip whatever feels irrelevant to you, these are just some ideas you can implement for a productive morning.

I took time to reflect on how I could improve as a person and have a productive day. As well as , setting goals to be achieved before the end of the day