My first Hooptober!! Gonna attempt to start off strong and try to complete it.

6 countries
Japan (Kwaidan, Tetsuo)
United States (Numerous)
Canada (The Brood)
South Korea (Train to Busan)
France (Diabolique)
Mexico/Italy (Santa Sangre)

6 decades
1930s (The Bride of Frankenstein)
1950s (The Blob, Diabolique, The Mummy)
1960s (Kwaidan)
1970s (Dawn of the Dead, Deep Red, Ganja & Hess etc.)
1980s (Aliens, Demons, The Blob (1988), Halloween II etc.)
1990s (Scream 2, Tales from the Hood, Misery)

7 second films of franchises
Scream 2
Texas Chainsaw 2
Aliens
Dawn of The Dead
Bride of Frankenstein
Halloween 2
Hellraiser 2

4 body horror films
The Brood
Tetsuo the Iron Man
The Blob (1988)
Altered States

2 films from this year
The Invisible Man (2020)
Host

3 disease based films
Train to Busan
Dawn of the Dead
Shaun of The Dead

The highest rated horror film from the 50s that you haven't seen and can access.
Diabolique or The Blob (1958)

1 film that is set entirely inside one location
Misery

1 Invisible Person film
The Invisible Man (2020)

1 Non Dracula Hammer Film
The Mummy (1959)

2 films with a black director or predominantly black cast or lead
Ganja and Hess
Tales from the Hood

1 film with a movie theater in it
Demons or The Blob (1988) or even Scream 2

1 Tobe Hooper film
The Funhouse or Texas Chainsaw Massacre 2