cannot delete files

If you do not already have a recent and complete backup, get a backup of your Mac. Now. NOW!

Here is:

... How to back up your Mac - Official Apple Support

Restart into Safe Mode, and try Finder again:

... Use safe mode on your Mac - Apple Support

If things start working better, and if you're running macOS 10.12, upgrade to macOS 10.13, or newer—depending on the MacBook Pro model year.

arlene142 wrote:

I do not understand.

You seem to have a corruption.

The cause is unclear.

One possible cause is a hardware problem. Failing storage, or some other issue.

Backups of your important data are necessary.

Backups are the only way to mark your data as being valuable.

If you have no backups, then you will want to try to get some backups.

Tap or click on the following blue text to learn ➡️➡️ How to back up your Mac - Official Apple Support ⬅️⬅️

Why backups? Because corruptions and failing hardware tends to get worse, until it stops working.

Once you have a backup, time to try some tests.

First, booting into Safe Mode.

Tap or click to learn how to ➡️➡️ Use safe mode on your Mac - Apple Support ⬅️⬅️

Then reboot the Mac normally.

Then run Apple Diagnostics.

Diagnostics can and will find some hardware errors, can miss others.

Tap or click to learn how to ➡️➡️ Use Apple Diagnostics to test your Mac - Apple Support ⬅️⬅️