Advice on Custom Template vs plugin?

I'm looking for general advice/strategy....
I want to have posts in category “home” show up as full text posts on the home page, and excerpts of posts from category “XXX’ show up on the “XXX” page.

What would be the better way to accomplish? A plugin like "list category posts" or modifying a template?
I am not very good with php, but I also like to avoid plugins because sometimes they cause problems on the site and/ or become orphans.....would the php method require a strong php expertise or is it something that could be gleaned from the php examples provided?