Making a Previously Built Site SEO Friendly

Hi all—I’ve only worked on building websites from scratch, and now I’m helping an arts organization with a pre-existing site. While we’ll definitely be incorporating SEO best practices during the redesign, I’m wondering if there are any specific challenges or opportunities I should be aware of, given that this site already exists and has established assets.

One idea I had was to rename audio and video files with relevant keywords to improve SEO. The site isn’t massive, so I could potentially automate this process.

We’re not aiming for huge traffic numbers, but I do want to make sure our organization’s name is strongly associated with the artists we collaborate with. Any advice or suggestions?