Is there a way to make film/Instax photos look like this?

No.

Filters cannot add grain. You can take an image and then ask someone to Photoshop it for you if you can't scan/photoshop it for yourself but you won't get a result like that from a modern film.

Get the highest ISO/ASA film you can find then spread some KY jelly over your lens. Shoot under the bright sun. Experiment with different amounts of KY jelly. If you want the corners to be darkened, put a rectangular frame over the lens.

Probably not. There's other lenses could attached to Instax 7s from Holga, which allows you to take instant pictures with effects like lomo cameras.

You cannot get Instax photos to look like this. If you want to get impressionistic photos like these out of instant film, you'll need to use something from the Impossible Project, not Fuji.

You can make the disposible camera, which takes 35mm film, look like this if you buy one of the underwater ones that has 800 ISO film in it. This means the film will be grainy. It will be even more grainy if you shoot in subdued light and the film is underexposed. Also, leaving the camera sitting in hot sun for a couple weeks will age the film pre-maturely, which messes up the colour rendition and can also encourage high grain.

Since disposible cameras have infinite focus lenses, you'll have to do something such as mearing vaseline on the lens to make the image softer. This what they did with old glamour photos in the 20's and 30's.

All this can be faked in Photoshop but instead of having grain, you'll have noise and the effects won't look as organic. Plus it takes the fun out of it and is somewhat deceptive to your audience who think they're looking at old, screwed up film.

Have fun experimenting!