How to detect the name of my current launcher? My phone is Galaxy A5 2017

The Android updated automatically to version 8.0.0

My launcher app has some problems - I can't find the Skype icon and I really need it. I have to enter Google Play, to search "Skype" and then to push "Open" to start it - but that's really crap

I want to try another launcher (at this moment I'm running the default launcher app).

But in case the new launcher is even worse, I need to come back to the default launcher.

The problem is that I have no idea what's the name of my current launcher.

The Android OS should facilitate the users such essential information!
Open Settings->Applications->default applications.
Tap home screen and select your required launcher.
(if you have only stock launcher(for Samsung devices, it will be Samsung Experience Home), then there will be only one present, if you've installed other launchers like Nova etc. , then there will have a list of launchers available. Selecting any one launcher will set it as default launcher of device)

As AndrewT said: When you install 3rd-party launchers(from play store or using apk), you just add more selections for the launcher, but not necessarily replacing it wholly. Or in other words, you can have 10 launchers installed on the same phone at the same time, but only 1 active launcher.