This movie is listed as a comedy, a horror, and a romance. The romance aspect is ok. It's not scary at all. The funniest gag is in the credits. Overall, the whole movie is incredibly stupid, and not worth watching, except maybe if you're a diehard fan of the web series.
The script is absolutely terrible. There are a lot of concepts that sound cool, but when you try to think about them and how they fit into the abstract plot they don't work. This feels like a first draft of something that could've been good. Nothing interesting happens over the course of the movie. It's not quite boring, but it is pretty cringeworthy at times. There's nothing that entertaining about characters being stupid. The story is kind of predictable as well, and there is very little tension.
The acting is also pretty bad. While Laura isn't quite as annoying as she is in the webseries (mostly thanks to the movie dropping the gimmick of her talking to the audience all the time (she is relegated to an exposition dump at the beginning)) she's still not good. Barely anyone's acting is good in this. There are so many scenes where it could've been somewhat dramatic if it didn't feel like the actors were just reading their lines. Anything potentially impactful is ruined by terrible performances. Not that there is much to ruin.
Probably the best thing about this movie is the visuals, and that is only because I'm comparing it to the web series. In the series, the whole story is told through Laura's webcam, making the visual experience so bland that it might as well just be an audiobook or something. Having the camera move around a bit makes it look better, but nothing too interesting or impressive is done with the visuals. Everything - not just the effects - looks really cheap. I wouldn't have minded that much but pretty much everything about this movie is unprofessional.
Overall this is a really, really stupid movie. The only people who will call it good are those starved for representation. Honestly I wish that more time had been spent on doing more than one take for each seen or maybe on rewriting some dialogue to make it more interesting or entertaining. It could've been good. If you really want to see the story of Carmilla, then watch the webseries on YouTube. Or watch any other adaptation. Or read the book.