1. id like the header image to be smaller when the screen size decreases
For this, I think flexbox is exactly what you're looking for! It *can* be kind of complex to get the hang of, but I learned through
flexbox zombies and it was a really engaging way to practice the syntax. It's free and to do what you want with flexbox, I think you'd be able to accomplish it pretty quickly!
As far as getting the image to display inline with the text, there's a bunch of ways to go about it but none of them are particularly beginner friendly. If you were to use flexbox, you could create a div column for the text and another for the image directly next to it? That's the easiest way I would do it, but that's only because flexbox is what I'm familiar with.