Just a note, please only answer the following if you have a cat or have had one in the past (or done research) Thank you! I've done tons of research, and my aunt/uncle have a cat that I care for sometimes!
So basically I want a cat one day, I met my aunt's cat and now can't stop thinking about them... I probably will never get one (as long as I live with my parents...) but I just am curious! So here are my questions...
1. I have no idea about cat diets, so whats better dry or wet food and if so is there any well known and good brands for cat food that I should know about?
Cats shouldn't eat dry food. The don't get enough water. I'd feed a cat a raw diet, since it has so many more benifits. The water content can help with their kidneys, coat and nails!
2. There are really young kids and a dog in this house, do you know of any really friendly cat breeds?
They don't usually vary by breed. Try to adopt or rehome.
3. Best grooming brushes for cats?
the small pet select brush is really good my aunt uses it. also furminator.
4. Suggested cat trees, toys, etc?
I'd recommend at least 1 scratching post in a room to make sure they won't kill your furniture. One large cat tree and multiple scratching posts should be sufficient depending on the space. My aunt's cat likes their cat wheel. They also like balls with bells in them. Try to get both independent and human interaction toys.
5. Indoor cat breeds (I'm too worried about the dangers of outside for a cat...)?
Do keep any cat indoors. Check your shelter nearby, cat rescue, petfinder, adopt a pet, etc.
6. Anything you'd like to add for me to know? 
Raw diets are best imo.
Pairs or more is the best from what I know.
Cat wheels are super fun! It's like a hamster wheel for a cat!
I'd say don't let your cat outdoors unless on a harness...i don't like the idea of outdoor cats.
adopt or rehome.
again raw diet lol.
Thanks so much in advance!!!!