Speaking from experience, my spm results were not that impressive as compared to others but still, got aggregate 17.

Take any AutoCAD class (basic/medium/expert) at any local college/U. Back then, 10 weeks course (only 3 days per week) from zero knowledge to understanding and mastering basic drawing/drafting.

Then, try to apply job as draftperson at any consultant firm (architecture/engineer/QS/etc). Work hard, go up from junior to senior (or whatever higher rank possible with ur spm results).

And no, I didn't finish my dip/deg due to family emergency issues back then, but considerating to further studies this year *hopefully*.

Additional bonus:
If u can do sketchup, u can convert 2D cad plans into sketchup 3D.
And, can touchup image with photoshop (or whatever image editor).