What are good problem books for beginners with advanced content but accessible exercises? I am going through Pugh's Real Mathematical Analysis. I like the content in comparison to Baby Rudin (ie. Pugh's first chapter discusses visualizing the 4th dimension, objects in $\mathbb{R^n}$, schroeder-bernstein theorem, construction of the real numbers etc whereas Rudin only covers the field and order axioms and some others) but doing the exercises is just looking up the solution after fruitless efforts of coming up with a solution 60% of the time and I dont see that as learning. Is there a problem book that helps with that? It has to correspond with the content of Pugh's book but with easier exercises. If there is such a problem book I plan on reading the chapter, do the exercises on the problem book then do the starred ones in Pugh.
This is my first exposure to Real Analysis by the way after reading the 1st volume of Apostol's calculus.