Zach is not an idiot, he's just an immature person and thirsty virgin at that. Jealous of MC getting all the girls he likes too.
Ignores Val while talking to Erynn and wonders why she's mad with him.
Val asks him to put her down and he won't so she gets angry he doesn't listen to her (which is a common theme) and he blames it on her being mad for losing.
Keeps calling teachers by their first name despite being told not to.
That fucking license plate.
Says a ton of shit about Elena she overhears while walking past then wonders why she says hi to the MC and not him.
Constantly harassing Layla and thinks he's actually "flirting".
Switches seats with MC despite being told not to and again wondering why Val is mad because again he doesn't listen.
Has so far managed to put off every single woman that drinks in the bar.
Thinks spying on te girls is a good idea.
Can't tell when he's being manipulated.
All that is just surface level stuff. Idiot is the politest thing I could think of to call him. I've seen wooden spoons sharper. Boy is a moron, pure and simple.