I can't have more than 1 post in a category?

Hi,

I’m new to wordpress. I have made a number of blog posts and a number of categorys. My blog is set to show the latest posts on the homepage. The problem I am having is if I add more than one post to a category, the posts seem to disappear from the homepage.

For example: I have a post called ‘black shoes 1’ and I have a category called ‘black shoes’ and if I put that post in that category thats fine. But if I try and put another post in that category e.g. ‘black shoes 2’ then both posts will not appear anymore on the homepage.

Also sometimes if I try and add a post to a new category it just will not show at all on the homepage unless I set the category to uncategorized and then it will show?

I’d like to have multiple posts in multiple categories and have the latest posts show on the homepage. Can anybody help? Thank you