Is this wrong of my dad to do?

You can learn to drive from ANYBODY who has a license. If you're in school, many of them have driver training classes. Find another source of instruction & tell King Sh!t to go pound sand.

This sounds like a silly condition to me, I'd never say this to my daughter.

Yes it is, because he should let you wear what you want to within reason. What you could do is wear pants under the skirt, because all he said was for you to wear a skirt, he did not tell you what you could wear under it.

yes

To clarify a long skirt, he wants me to dress modestly

Because apparently jeans are too much

That sounds very strange.