What is the difference in actual meaning/usage?
The example is from https://hanasu-eigo.com/2017/01/11/325/
“I’m excited!” というのは、「すごく楽しみなことがあってワクワクしている」というような時に使います
and then had an example below:
“I’m going to Japan for the first time. I’m so excited!“
I've read and listened to enough that I would know if someone was excited about something, but if I used the words themselves, I imagine I would end up using ワクワクしている more often than natives would (where they would simply use ワクワクする).