It’s to understand the background characters and the people you will see in the future the first story you get to see all of them but it’s matter that much unless you want to see more of the personality because for this story the bottom you get to see his personality more in the first story and the seme personality in the second
No, "Kiss me if you can" isn't that important, the stuff you need to know from there is mentioned in Desire me if you can. It's actually Kiss me liar which would make more sense to read first, but the main story is pretty toxic and not everybodies cup of tea. That is concerning the manhwa adaptions. If we go by novels, that would be different, there it could be interesting to read some others before.
If you are asking from the Universe point of view as a whole,
Eat me up if you can, Lick me if you can and Desire me if you can holds the most importance. (I am not considering Kiss me Liar here).
Kiss me if you can is good to start for a rough idea as later the story becomes more complex and more revelations. But Kiss me if you can portrays a very biased and half knowledge as this story is from chase pov and Chase don't knw anything about his own family history.
Runaway if you can and Deflower me if you can can be read after these as well.
This is for better understanding of the things that are going on. Otherwise every story is good enough to read as standalone. U can start with anyone

Help! In what order should I read all this series?