I think I'm going to be the only going astray from the pack on this one.

Your light/dark blue blocks are square in a squares. You could, if you had enough fabric, remake them all. BUT, use only squares to put them together, no bias no stretch, you could cut off the access fabric once they are complete and it's easier for a beginner to sew...or at least it was for this beginner. There's a tute about it here from Shelly Q.

If you don't have enough fabric or don't want to go to all that work, and I don't blame you, Patrice is right. The only person who's going to know it didn't turn out like you wanted it to is you. Pick an option about squaring off that works best for you. You are the one that makes it.

I laughed when I read this, "why all beginners need to use patterns". Believe me, we have all been where you are at one time or another. I agree with most to make the small ones, one size and then cut the squares to that size. You will lose your points. but only you will know it wasn't on purpose. When I make up a pattern, I first make a sample out of scrap "to make sure it works. I am challenged in "the making your own pattern area" also.
I do my pattern on graphed mylar, then add the 1/4 in to each piece for the final pattern size. I'm sure there is an easier way but this works for me. If you don't have 1/4 in foot on your machine consider getting one, it is a big help to keep your seams accurate. It is my favorite tool and has made a huge difference in my seams. Don't get discouraged, it'll look fine, it'll have personality. Show us when you're done.