ArtiZanni wrote: …How to do this smart album and is it safe to do so ;)
muguy suggested a Smart Album, because Smart Albums are one of the most powerful tools in Photos on a Mac. (And, unfortunately, they are missing on iPhones and iPads.) They don't change anything-- they collect pictures into albums based on the criteria you set. As with any album, a picture being in a Smart Album doesn't change its status with any other album or folder.
You can make a Smart Album with the menu File>New Smart Album.
I have lots of Smart Albums! Some I generate to meet specific need. But here's one that I have available all the time:

I've included a "Date Captured" requirement, because often I'm looking just for the recent pictures that I've neglected, but that's not at all necessary for you-- you can have just one condition or many, and you can find pictures that meet "all" or "any" of the conditions.
What's cool here is, when you have this Smart Album open, and you drag a picture in here to one of your regular albums, that picture immediately disappears from this Smart Album, because it no longer meets the requirement of not being in an album!
I have whole scads of Smart Albums:

I have folders of folders of Smart Albums.
You might learn more, here:
Create Smart Albums to group photos and videos automatically on Mac - Apple Support (SG)