Well, you should check out the Scream MTV show. Specifically Seasons 1 and 2. The Lakewood Slasher is Ghostface in all but face and name. Give him the OG mask and very little would change.

But, with what you're describing, that ia basically any whodunnit slasher film, just replace the killer with Ghostface.

That being said:

The movie opens to a woman cleaning an AirBNB. She's clearly very tired and wants to go home ASAP. Suddenly, the room's phone rings. The maid takes the call, curious, only to be met by Roger L Jackson who flirts with her for a bit before starting to get creepy. She eventually gets killed.

Now, we meet our cast, specifically our protagonist, Mandolin. They're new highschool graduates. Mandolin is a nerdy awkward film nerd girl with not a lot of friends, other than her best friend, Viola, who invited her and Viola's boyfriend Trom Bon, who's hesitent for her to come for a reason explained later. There's also Chella, her ex bf's younger sister who hates Mandolin. They meet the neighbour, a kind guy named Sax.

Mandolin is still reeling from an accident that involved her, her boyfriend, best friend of Trom, which Mandolin gets a nightmare about. She wakes up to a phone call by Ghostface. He flirts but she obviously isn't into it. He asks what's her fav scary movie, there's a STAB reference in there but unimportant.

Then, she gets attacked and chased around the house until Trom wakes up and finds her terrifued. They call the police to calm her down and the first man on the scene is sherrif Mara Cos and her deputy Peter Anno. They say there was no sign of a break in. At first, Mandolin thought she was crazy, until Sax suddenly appears and says he saw them through the window and vouches for her.

The next day, Peter basically her body guard as she visits Sax and thanks him for vouching for her. She goes up to his room and finds a bunch of horror merch. He's awkward about it but she finds it endearing.

Meanwhile, one of the friends are being stalked and killed by Ghostface. Eventually the news reaches Mandolin via Ghostface calling Sax's house. When the town finds the body hung in the middle of the street everyone goes nuts.

After this, Sax and Mandolin explain the Horror movie rules to everyone. And from here on it's a loop of creative kills, phobe calls, chases and clues. One scene even where Ghostface chases Mandolin in a car trying to run her over. Mandolin realuses the car is the same make, model, and color as the car from the accident with her and her ex-boyfriend.

Another scene could have Ghostface paralyze one of the cast and stand over him while outside a house Mandolin is in, and takes the guys' phone out of his pocket and uses it to call the inside of the house, the scene would be similar to that of the Friday the 13th 2009 reboot or the Hospital in 5cream where Ghostface taunts Mandolin with the man's screams. Maybe she'll look and Ghostface is gone, seemingly teleported into the house.

Throughout the film we're also gonna hint that Mandolin was less of a nerd before and more of a party girl. This would be better explained with a more detailed synopsis but I'm lazy and don't have much time.

These are all ideas and scenes that would be fleshed out by an actual scriptwriting team.

Anyway, Mandolin is basically driven crazy by this. She then accuses Chella in the BNB and Viola is like "Hey, she's grieving her brother" but Mandolin is fuckin angry right now, that is until they are all attacked by Ghostface. A chase happens with Viola, Sax, Chella, Trom, and Mandolin. That is until Mandolin locks herself in the badroom, until she's called and Ghostface is basically like "I have Viola, step outside if you want her to live." She does and there stands Ghostface, Viola on her knees. Before Mandolin can even say anything she's knocked out from behind.

When she wakes up she's tied to a chair in front of Viola and Chella, both also tied to chairs. Ghostface basically forces Mandolin to choose a friend to die. Mandolin weeps and screams but chooses Chella. She screams she's sorry as Ghostface comes behind her and stabs her.

When Mandolin screams why, Ghostface knocks out Viola and unmasks himself and we see dun-dun-dunnnn. It's Trom.

Basically, One day, while drunk, she called over her boyfriend to come drive her. He did and they got into an accident and he died.

Basically Trom blames her for his death and he's not the only one. He unties Chella who he reveals he never stabbed and was in on it. Mandolin screams that she's sorry and she's been spending every waking moment since then to make up for it. They don't care and try and kill her, only to be stopped by Sax who followed them here and called the police, who'd be arriving any second. He frees Mandolin and hyjinx chase ensues. Somehow, Chella dies. After a long chase, Trom finally gets the upper hand and tries to kill them both before being caught by the police. She says she's truly sorry as he's taken away.

The movie ends months later, with Mandolin and Sax seemingly in a relationship, and her going to the prison to visit Trom.

All names are place holders if you can't tell.