I trying to draw a flange that is the shape of a straight slot. It has holes all the way around it. (As per pictures below)

I've tried all the patterns. And I was trying to make the contour lines for my slot all one so that I would be able to use it as my guide line for my holes and they would continue all the way around but I couldn't figure it out either.

I am new to solidworks and I don't have much experience with it. I took the Essentials and the Weldments course.

Thanks for your help.