Okay, so I've seen this dude pop up relatively frequently, but I genuinely don't recall seeing him in the show so... Who the heck is Wes Weston??
I'm relatively new to the Phandom myself, but from what I understand Wes Weston is a background character that has gained personality and infamy through the fandom.
This guy here specifically. He has absolutely no significance in the show.
The premise behind his characterization is that he's a conspiracy theorist who correctly recognizes that Danny is Phantom-- but no one believes him (and sometimes it gets uno-reversed onto him since he looks like Danny).
His entire shtick is trying to convince other people that he is right. He's usually used for humor, with Danny either being exasperated or annoyed with Wes, or outright messing with him. Wes Weston has a brother, Kyle Weston, who is depicted as his opposite.
Kyle (the dude on the far left) doesn't believe in ghosts; he recognizes that Danny is Phantom, but he doesn't think Danny is a ghost to begin with.
They're both pretty much Phandom-created entities. I've seen a lot of division on the character. People either like the character, ignore him, or hate him. I can see the fun in his character, but one of the biggest criticisms against him is that he outshines some canon characters in the Phandom-- most notably Valerie.
Valerie's room in the show is papered with a bunch of articles on Phantom-- and she's already obsessed with (beating) him-- so there's sentiment that she would fill the conspiracy theorist role much better (and that she does deserve more spotlight than a random white boy design in the background).
Tho at the same time I do think you have to tweak a lot of Valerie's character to achieve the particular blend of conspiracy theorist that people seem to like with Wes, so I Do get why people gravitate towards him for certain ideas (especially with him resembling Danny).
I'm sort of on the fence with the character myself. I think he has potential and the concept is fun-- but that people are right Valerie and other characters could use more love and/or be used in his place.
But that's just my perspective as someone new to the Phandom, so I could be missing certain things.
I actually like the idea of Kyle as a character more lol