He didn't stalk her. Stalking is unwanted and/or repeated surveillance of someone. He couldn't stalk her or track her because he didn't know anything about her.
He might lack social skills. He did go over-the-top in his cringe effort trying to locate her - ads and social media posts.
It's creepish behavior but would have been forgiven and treated as romantic had she found him attractive, was single, and wanted to date him.
In the era of social media every woman has instant access to 10,000 men willing to jump her bones within a 1 mile radius. Unless you have some fame and deep pockets, you're going to come off as creepy.
Justin Bieber did something similar a few years ago using his enormous fan base to help track down the identity of a female he thought was pretty and had never met:
https://entertainment.ie/trending/j...stery-girl-for-him-and-she-aint-happy-357117/
If anyone was calling it creepy, it was a small quiet minority.