Get a cheap camera, takes some mates to the woods, get them to swear and panic a lot, hang some dolls in the trees and call it Blair witch.
If you're grammar and language skills suck, write the script anyway and send it off to a professional proof reader or get a full copy edit done. For a 10,000 word script it shouldn't cost more than £250.
But remember even the principle photography of Blair witch cost $20,000 the final cost with production, advertising and all the other inflated rubbish that goes into making Hollywood movies cost somewhere between $500,000 to $750,000.
And remember these costs were for a movie made back in 1999, so it's going to be more in the region of $1 to $1.5 million I expect.
Ultimately, don't expect to make a serious movie if you're not willing to spend money, or more likely, don't have any.
The alternative is to make a youtube movie, for that you just need someone's camera phone, a comedy plot a copy of Power Director 10 and Adobe After Effects if you want to do the special effects thing, you can get that on a monthly subscription for £75. All you need then are some friends who don't mind making

of themselves to a world wide audience.
Dreams are all very well as motivators, but you need to set out a budget, get your script finalized and then start convincing people to help then the money you get from youtube adverts might see you through to your next project. In a few years time with some experience and other projects under your belt you might be able to make your horror movie.
P.S. we've all sold our souls to the devil, like god he goes by many names.
Microsoft
Apple
Sony
Samsung
BP
etc...
After all when was the last time you read a software license agreement?
P.S.S.
For gods sake, hire an artist that cover graphic scared the pants off me, but not in a good way