Don’t stress about it @_serge. I was confused by the relation between Kits and Patterns at first as well.
It’s frustrating because you just want to get stuck in to making music - and Kits and Patterns are the first concepts you come across that are not intuitive (not to most of us anyway).
What really helped me was to use @void 's Tabula Rasa project sysex (There is a link to the file at the end of thread - load it to your A4 using the C6 app)
This has empty Kits labelled A01 through H16 in Kit slots 0 -128 used by their respective Pattern.
In other words, you have one Kit per Pattern:
Pattern A01 uses a Kit called A01 saved to Kit slot 001.
Pattern A02 uses a Kit called A02 saved to Kit slot 002… and so on, up to…
Pattern H16 uses a Kit called H16 saved to Kit slot 128.
There are advantages to the way Elektron designed the Kit/Pattern hierarchy that will become apparent as you get to grips with the machine. For now though, you might prefer them to be linked one-to-one.
Don’t be disheartened by the steep learning curve - once you are over the edge, the view is incredible! 