I have never been to Disney alone (though I will take time to hang out by myself) BUT when I travel for work I usually end up with weekends free. As a parent I’m so used to thinking about what would make my family happy, so it took me a while to get used to the idea that I could do exactly what I wanted to do. It’s totally on me to decide if I feel like going to the beach, or the mountains, explore a new city, or spend the day at a lake. I can skip that “must do” thing because I don’t feel like it, or wander a bit instead of taking the bus because the sun is shining and it is a beautiful day outside. I miss my family so much when I travel, but I have come to really enjoy these weekends away.
So no tips except be incredibly selfish with your time. You’re there to make yourself happy and no one else. With 7 days you can splurge for LLPP at MK and HS if you like doing rides, buy LLs for Guardians every day just because, and still have plenty of time to get lost in World Showcase, or wander down that path at AK that you always skip because it’s “boring.” If you see something that your family might like (I usually buy chocolates from unusual places) pick it up so that they know that you were thinking of them. But otherwise, celebrate that this time is all about you.
Have a great time!