Overall you are doing good. You really need to watch matching up your corners and points. Each "intersection" needs to be carefully nested together, pinned, and sewn to be sure that they come out lined up correctly. Your seams need to match up. Try pressing each block and sashing strip as you sew them together...it makes it much easier to get the seams to match up when the piece is pressed flat. Don't forget to pin everything, especially since you are a beginner. You'll get it....it just takes practice.
Oh, after looking again, you MUST maintain 1/4" seams so that each little square of your block comes out to the same size as all the others.
Keep going. It gets easier.