How to do this feature in solidworks

Here is one that look similar to your hand sketch.

I used surfaces to match your sketch and also patterned it around.

I slice the curved edge from the right plane, mirror and pattern, then slice the outside round edge from the front plane, and pattern.

Here is the 16 vs 10 version you asked about. I forgot you don't have SW2017

simplify your geometry
and probably you will see how you want to do it

see the difference between what im asking for and Richard ring