Don't be nervous. I admire that you're willing to expand your horizons and learn something new.
A few years ago, I designed a miniature quilt that had curved piecing. It was very difficult. I kept making mistakes and finally put that project aside. Made several other quilts before I picked that one back up to discover that I had gained some skills and experience, and was able to piece those curves successfully!
So, what I'm saying is, if you love that quilt, buy the pattern and practice on scraps. If you're not good at it, you can either keep practicing, or you can put it aside for 6 months or so while you work on other projects, then try it again.