Angle bracket design

I don’t see an angle bracket, just a flat plat.
Add a top view image.
Where are the screws to be located?
Have you had a Statics class? A Strength of Materials class?

SWComposites:

It's just a typical angle bracket shape, I've added a another image to show.

Yes I have taken a class with statics as a portion, didn't really pay too much attention in it as I was initially going into electrical engineering rather than mechanical. I think I have a general understanding of what I need to know by the end of this problem (bending stress, shear stress, things like that), I just don't know how to start. Is this something I can just analyse like a cantilever beam?

Assuming the column is a square hollow tube -
you have two joints to analyze; a) the object to bracket, b) bracket to column
for each joint determine the loads in each fastener: for joint a) should be a simple 70N / 4, assuming the object is centered in the fastener pattern and does not cantilever off the bracket too much;
for joint b) draw a free body diagram of the bracket with each of the fastener loads reacting a vertical shear load and a moment at the bracket corner, where the moment is 70kN * 250 mm/2; now the vertical shear load results in an inplane moment about the fastener pattern center, and the corner moment results in out of plane prying reacted by fastener tension in the upper two fasteners.
for each fastener location check: a) fastener shear, b) bearing in the sheets (accounting for edge distances), fastener tension
and check the bracket corner for shear stress
and depending on the dimensions, check the bracket corner area for buckling

SWComposites:
Thanks so much for the guidance!