How do I free up internal storage if I don't have any apps downloaded?

I have an Android Voyager, RCT6773W22B. It's version 5.0. When I first got it, and years after that, I could download at least five apps downloaded at a time and have a great sum of pictures in my gallery. I would still have space after this. Over time, I would delete apps I didn't use anymore. If I wanted to download something else and there wasn't enough space, I would delete apps and/or pictures I don't need. Now, I can't download anything due to internal storage. I have no apps, five pictures (not taken with the camera), and I've cleared the cache on everything except Chrome. It tells me my internal storage is completely full and I can't move anything to an SD card. What do I do?