I recommmend you look at the introductory booklets by Alfred Publishing Company that are aimed at providing a step-by-step introduction into the piano works of many central composers. Although I generally dislike Alfred, these booklets are very good in that they indeed pick a fair number of easier pieces that are nevertheless very satisfying. There is one for Bach that seems to be the only series that provides a truly gradual course that introduces a new concept with every piece.
There is one for Chopin too, and it does start with the Waltz in A minor (posthumus). IMO, this is the easiest and at the same time the prettiest of all Chopin Waltzes. Some of the Preludes are also easily accessible and beautiful, particularly the one in E minor (Op. 28 No. 4), which is very haunting and provides ample opportunity for very expressive playing for such a technically easy piece, and then of course Barry Manilow's Prelude in C minor (Op. 28 No. 20), to name just two.
There are also short general introductions for how to play ornaments, style notes, pedaling, etc., but this is where I have my major beef with the Alfred books. The editing can be a bit controversial at times, so it's best to use the choice of pieces as a guideline, buy a good edition if you want to play any of them and discuss the details with your teacher.