Since you never used reddit you are not allowed to create a subreddit.
I don't know exactly right now but I think you need at least 5-10 posts to create a subreddit.
I like the idea to create social media accounts, but I don't think that you will succeed only with scripts. People will not follow you for this autogenerated posts. Maybe some, yes but you need to interact with them.
https://www.youtube.com/watch?v=EhqZ0RU95d4