Almost all of them are first love (I'll make sure to mention which one of them isn't).
There is no cheating between the main couples.

The rating is subjective so anything with a rating of 7 or above, you should definitely give it a try!! (Because 10/10 is for novels with tropes that I personally enjoy)

I also have tried to put similar novel genre/types together. Serialized:
[1 High School/University]     [2 Slice of Life/Romance(~y)]     [3 Online Games/Esports]    [4 Entertainment/Actors /Singers]  [5 Crime Investigation]    [6 Sci-fi / Futuristic]    [7 Unlimited Flow]    [8 Xianxia / Wuxia / Xuanhuan]