is there a plugin that you are aware that would help

is there a plugin that you are aware that would help in changing the name of the theme, if not do you know what folder the name of theme is, I'v been searching its within the H2 tags, somehere. I believe perhaps within the wp-content, themes, folder, etc. exactly where I can't find it. I would like to change the name without breaking the project, could you please help, thank you