Are there themes that allow for the following?

Hey there! I want to create an interactive site that allows me to post my content (stories) and then others to post pre-approved comments. I'd like to have a social media component if it doesn't all have to be, if that makes sense. I don't want anyone to have to set up an account to comment, but would like to have that be an option if they want to. Is there a theme that will allow both? Like a social media aspect for people who want to get involved/comment often and also allow for those who just want to drop by once (and not set up an account)? Or one that uses Facebook directly so they don't have to start a new social media account? Essentially and eventually, I am going to have a contest and have people make suggestions/comments on titles and then have them vote on their favorites, so I will also need a poll but one step at a time. Right? Exhale. I want to advertise the site on Facebook (not officially - just through friends) so I guess that's also down the road - plugin? This is all like a foreign language. I've never created a website and am feeling a bit overwhelmed. I'm a writer, not a tech girl. But I've made it this far and am putting my trust in the great minds of this community. Thanks in advance for the help!