Digikam is the KDE equivalent of Picasa, or maybe Shotwell with the ability to handle large collections of video and images. It can also import your pictures, adjust meta data, tags photos, export them to social media and a whole lot more. It even has basic facial recognition.
If I had a criticism about it it is that it can be a little confusing on the import process but once you have done a little research and decided what settings are correct you never have to do it again. It really is my favourite program for photos on Linux.
To install Digikam on KDE neon open Konsole and type,
sudo apt install digikam
Enter your password and answer any questions and Digikam will install. After installation you can find Digikam in the Applications Menu either by searching or under Applications/Graphics.
Tips and tricks
There isn't a lot I do to Digikam but one thing I do every time is to change where the database is on first start by placing it in a hidden folder. To do this on KDE neon just place a . at the start of the folder name. You can see hidden folders by using Ctrl + h.