Hi,
It’s nice to see a pre-University portfolio on here for critiquing, well done!
My input would be that you show a good, early understanding of drawing, idea generation, CAD generation, rendering etc, all of which you’ll be expanding on massively during University, and during your working career.
I would second some of the earlier comments about cleaning up and simplifying the layout. I always prefer to see hand-written notes next to sketches, but this is no big deal.
I’ve always thought that being able to draw nice looking arrows is key to not ruining an otherwise nice sketch. Your overly bold and blocked-in arrows on your action cam distract from the drawings, so try and keep these simple. When applicable, I make make sure my arrows sit on the same perspective as the sketch itself, which helps how they relate to the drawing.