You should look at this document:https://pianoforum.net/Graded_Pieces_All.xlsYour friend probably has level 2-3 . He should try pieces for that level. You can found most of the pieces at www.sheetmusicarchive.net, orwww.abrahamespinosa.com/partituras2.htm, or www.free-scores.comIn my opinion, Bach's Anna Magdalena Book, Burgmuller etudes and Chopin easy waltz (Posthumous) are a must. Everybody begins with that . This is not a serious argument, but those pieces are really nice and pedagogical. It is too early for Moonlight Sonata (even the first movement).Also at the beginning he should try only pieces he likes. He can hear how they sound (midi files) inwww.classicalarchives.com
Brahms' Intermezzo in A minor is 8?! If it's the one I'm thinking of... It's grade 9 in Canada, which is like 6-7 in ur thing...