This is a very important piece for the band world, and consequently for euphonium players. The first 8 bars are for the tuba and euphonium sections, and anyone looking briefly at the notes would rate it as super easy. BUT... we have to play it softly and together, which is one challenge. Another challenge is that there are lip slurs that can cause one to stumble a bit. Here are some tips on smoothing those dependably, based partly on info gleaned from the 2 Lehman books and the Brasch book, and partly on my own use of alternate fingerings.

https://youtu.be/1a8-PltalRs