This is Leçon IV, Op. 60 by Fernando Sor (1778-1839), from Delcamp’s second collection, available once you register free of charge for the Delcamp forum.
Sounds simple enough, doesn’t it? With its single line of melody – “monophonic” in music terminology – you could be forgiven for thinking it’s easy to play too. But this is technically one of the trickiest pieces I’ve learned so far. The lesson here is about stopping notes from ringing out for longer than their notated durations. You not only have to play the notes but you also have to damp the strings with specific fingers of the left hand as well as the thumb of the right hand. Combine that with alternating between the index and middle fingers of the right hand and you have some formidable fingerwork for a beginner.