[AC Question]

receive error message when downloading ap. How can I download?

[STARGATE]

Unfortunately if your phone has 16GB or less of storage, you're out of luck.

You could delete apps that aren't needed or used.
Some apps can't be deleted, but can be disabled.

[lillywhite555]

Try Space Cleaner, it's basically a junk and cash cleaner, with the additional functionality to also manage apps, and ultimately increase space that is hogging your android device. It's super easy to use. I found it on Google play store, just type Space Cleaner Uniblue.