Ohohoh I knew it would look amazing! And it so totally does! I have the family one Dimensions do and absolutely can't wait to get started on it. I've not seen this one before though. So lovely!
Don't worry about the speciality stitches, if you ever need any help, just ask. I'm sure you'll get a plethora of advice on them and they won't seem so bad afterwards. I must say, I'm really impressed that you chose such a design as your first one. I did like a 3" one with only cross stitch and backstitch. And I was only three lines into it when I came crawling for advice

So you're doing so much better than I did!
As for the hoop marks, don't worry about them. Once you've finished your design, if you put it between two towels and iron it, they should come out. I've heard that tissue paper between the hoop and the fabric works, but I'm not convinced.