Okay, well I’m sure this is one that few people have problems with these days. Sites like Pexels (integrated with WordPress) provide royalty-free pictures and videos. Pixabay is another one, there you can submit photo uploads to avoid ads. As with any site, you can search “alternatives to” and the site name to come up with current variations, you do want to check and make sure that whatever you use is royalty-free, though. http://morguefile.com is yet another.
Custom photos are a different story, probably depending on the subject matter but you can always try fiverr, same as for art or graphic design.
As for the more non-PG stuff, I’m sure you shouldn’t have to look hard, customs likely vary depending on the performer, etc.