Looking for someone to help me understand how to do small things in Javascript

Hi, so I'm using PouchDB & JS to build a film review website (locallyhosted), all is looking good so far, but there are 2 things I want to do on it, and I just don't know how, so I'm looking for someone that'll help me learn how they work. 1. I'm pulling an image from my database to my main page, but I'd like to recreate the overlay hover effect, but when the image is hovered over, the title of the film is also pulled from the database and shown ON the image. 2. I have a basic sort by ID ascending/descending function working right now, but I also want to add a filter function to select a genre and hide any films which aren't listed as being in that genre. It's a very basic, quick job if you know what you're doing, I'm just afraid I'll mess up everything if I start adding new variables etc.