Dan,
Things you are possibly not aware of;
Every time you complete a portion, hit SAVE. You remember the saying, "Jesus Saves." Later, if you mess up, Close Without Saving. Re-open and you get back to your last save.
Another thing you can do if you mess up is EDIT - UNDO LAST MOVE. (You can keep doing this as needed.)
To delete the Red, often it is hard to find the sweet spot for clicking the Red. When you do, look on the lower left to see if you have in fact found the Red.
Most importantly, when looking for the Red, enlarge the heck out of the screen. You can either use the plus key on your keyboard or use the magnifying tool. I find this works wonders.
Hope this helps Friend.
jerry