Let's start with the moon! She's bright & full of... something?
Are these movie titles or book titles?
If they're related, they might all be from the same series!
Which book in the series is each of these from?
These are book titles from the ANIMORPHS series. The books are fifth, seventh, third, and first in the series (5731).
Solving the first puzzle may help you with this one!
What was the name of that series again?
What is the fourth letter of this title?
"M" is the fourth letter of ANIMORPHS.
If you follow the rules going around the moon for the word ANIMORPHS, you get the name MOIRA.
Those are some long pieces of text on the back!
Each word seems almost twice as long as it should be.
Odd that each couplet of letters are so close to each other in the alphabet...
... in fact, each couplet has one letter in-between where they are in the alphabet.
IK//TV//RT//SU = JUST
Your fully deciphered sentences are the following:
Just going down one side of River Street you can get two kinds of chocolate! You can't get any on Forest Street.
Be careful not to walk in Daniel's yard! He'll be mad--he's retired, and spends all his time taking care of his lawn.
Erin is almost always at work and never in that huge, blue house.