I suggest you research magic first and how it works.
You cannot change into anything. You cannot alter your dna in any way with magic. It is impossible.
The reason there are transforming spells on here is to bring money to the site, therefore so the site can be updated.
Learn the basics of magic first such as meditation, centering, grounding, energy manipulation and visualization. These can be searched for in the forums or using the search bar in the upper right hand corner.