Simple:
* The young fan was starstruck after meeting her favorite singer.
* He became starstruck when he saw the famous actor walk into the restaurant.
Descriptive:
* The young actress was completely starstruck by the legendary director's presence.
* His eyes widened in starstruck awe as he listened to the famous musician speak.
Figurative:
* The city lights made her feel starstruck, like she was gazing up at a million twinkling stars.
* His success story was starstruck by the media, making him a household name overnight.
Humorous:
* I was so starstruck by the barista that I forgot to order my coffee.
* She tried to play it cool, but her starstruck grin gave her away.
Choose the sentence that best fits the context and your desired level of formality.