You have to secure your space with the property owner most spots cost around $2000. You also have to get an inspection from the health department and then get a business license(mine was $77) then pay the city $1000 and the state $600.
Like most others, if your neighborhood is not an active one over Halloween, then you can go to a public one. Malls, churches and others hold events like trunk or treat and so on. Check your newspaper.