I'm looking for some lakorn to start off with since I'm fairly new to the genre. I'm intrigued by the slap/kiss plot and am looking for one with a happy ending.

Thank You.

This Genre most likely contains sexual assualts, rape, females treated very badly 

Try "Sawan Biang", if you like it there is a whole lot more but with lots of plot holes, things that make no sense and predominant stockholm syndrome
King Gor Rah Kah Gor Raeng, Rahut Rissaya, Roy Leh Sanae Rai are my favorites. And of course I 2nd Sawan Biang, which is like the ultimate slap n'kiss. The heroines in most of these are pretty strong, and most take a long time to forgive the male leads, which is why I like these.

You could try Game Rak Game Rai, or Roy Marn, both have good chemistry between the leads and plenty of slap/kiss action.