Greetings!
Today's exercise is quite interesting as it involves various features such as the creation of additional Planes, Extruded Boss/Base and Cut on a rounded surface, Mirroring items, and the creation of a Rib. I am posting images of the Part as it progresses till its completion. This sequence may help you, if necessary, to build the Part step-by-step. Have fun.
NOTE: Pay special attention to the
Property Manager section ("Box" on the left) as you go, it will give you an extra idea of what is going on during the building process.

THE LAYOUT
1st. STEP: SKETCHING THE MAIN PIECESelect the
FRONT Plane as your sketching Plane.
Pay most attention to the inner lines (Base, Vertical Lines and Arc), the outer part was "replicated" using the
Offset Entities feature in the
Sketch mode. This feature does help save some time and work.
2nd. STEP: EXTRUDED BOSS/BASE
3rd. STEP: CREATING THE RIBUse the FRONT Plane as your sketching Plane.

4th. STEP: MIRRORING THE RIBUse the
Reference Geometry command to create an additional Plane (In this case, Plane 1). It will serve as reference to Mirror the Rib you just created to the opposite side of the Part.
5th. STEP: CREATING THE EXTRUSION (BOSS/BASE)Again, using
Reference Geometry command, create another additional Plane (Plane 2) which will serve as the
Sketching Plane for the extrusion on the upper surface of the Part.

6th. STEP: CREATING THE CUT (EXTRUDED CUT)I used the
Offset Edges command to "replicate" (inwards) the existing sketch to create the section for the Cut.
7th. STEP: CREATING THE ROUNDED SURFACESUse the
Fillet command to create the rounds on the edges shown on the following two images.

8th. STEP: CREATING THE HOLE (S)I utilized the
Hole Wizard command for the first hole, then reproduced the remaining three holes in two
Mirroring steps.

DONE! HERE YOU HAVE IT, PART IS COMPLETED!I hope that you had a fun time. If you have a question (s), contact me.
Keep posted, there is more to come.
ANOTHER VIEW MODE