How do I modify the vertex coordinates of a drawn sprite?

[AiriableConditions]

I've been working on adding a 3rd dimension to the game, but one of the issues is that I can't draw the faces of blocks other than the front and back faces, since in 3rd dimensional shapes, visually, non-rectangular shapes are used. Currently I'm just drawing flat colour instead of using a sprite since I can't figure out how to change the coordinates of the vertices of a sprite. If it’s possible, can anyone inform me how to code it in?