I’m super new to journaling, what’s a good format to stick to?

Well, I would suggest you just write down your thoughts, feelings or situations. Don’t worry about grammar or spelling. Just write. I too used to feel there should be a format for journalling and there are so many formats online. I found that the more I write the more I found the format that works best for me. Just write, you’ll find the format that works best for you.