Prior warning, if it’s relevant: I’m not a tech

Using a Samsung J3. Suddenly problems with Google Play Services, with the message that unfortunately, it stopped. I took the following steps: 1. In apps, I forced stop, cleared cache and restarted but didn’t work 2. Then I uninstalled Google Play Services with a view to reinstalling 3. Wasn’t able to reinstall from the phone itself, so I switch on the setting to install from other sources and installed it from the internet 4. However, it’s not in my list of apps now, even though I think it installed

So basically when I try to open Google Play Store, no reaction. When I try to open Play Music, YouTube, Gmail, maps etc, I get the message to update, but pressing on update just brings me back to main screen.

Any ideas?