All dimensions are in inches.
Use AutoCAD or Solidworks. If you use AutoCAD, it is best to have both parts (and assembly) as 3 separate .DWG files. Create working drawings for the "RACK SLIDE".
a) Create a detailed drawing of the CAP
See solution: soln BASE, RACK SLIDE.pdf. Use this as a basis for creating a detailed drawing of the CAP
b) Create a detailed drawing of the BASE. You can use the PDF solution in part "a)" to check and revise your work, or simply "copy draft" - you will still "learn something".
c) Create an assembly drawing that shows the CAP and BASE assembled with the two fasteners. Show a bill of material that includes the McMaster-Carr part number of the fastener you select. You determine the proper type of fastener and material to use.