Welcome to straight shaving!

I found when I started that the 5/8 was hard for me to use. I am now using a 6/8 Dovo and it has the extra weight that I like and it seems smoother to me. Just my experience.

I would also say that you should not rush it and each time you shave it gets easier. Each time you shave you gain more and more confidance. Try different angles as you go along but do not push yourself into a nick, scrape, or cut. Start out slow, enjoy each shave and it gets better and better as you go on.

Good luck and enjoy!