Hi! Welcome! Read this https://steemit.com/steemit/@fatboyjames/a-simple-guide-to-markup-styling-how-to-make-your-posts-more-attractive and this https://steemit.com/steemit/@steemitguide/markdown-and-html-code-guide-for-beginners-that-includes-5-useful-tips-to-edit-posts-and-comments-using-the-raw-editor to better understand how to style posts.