Not to steal anyone else's thunder (I'm not gonna name names), but patience will be your most valuable tool. I am also a newby, 9 months. I have made several kits and they are drinkable at the bottling date. They improve slowly over the next couple of months, but almost from one week to the next, around 3 months after the bottle date, your wine will be better than what you regularly drink (my assumption of course, but better than most low/mid priced wines), beyond that they just teach you to pay attention as flavors develop.
The most important thing to know is that these kits are designed for you to succeed. All the fail safes are in place in the kit. Follow the instructions, and don't stress. Don't worry about oxygen in Primary, after that, keep it sealed under airlock to keep it out.
It is a good idea to verify that your fermenter volume matches your carboy volume. My first batch I filled my primary to 23 liters and I was short 4 bottles when I moved it to carboy. You do not want to fill with water, it will pull the kit out of balance, but you need a full carboy to keep it from oxidizing. You can weigh water to get your true volumes, but this is one of the few variables outside of the kit instructions that we can inadvertently overlook to throw things out.
As you have noted this group is very welcoming and helpful. Everyone wants you to succeed and we are happy to help. Notes are your next best friend. I still look back at wines I am drinking for insight.
Welcome to WMT!