What would be the recommendation for a easy first tremolo piece
that would also be easy to find the music on line?
Or is recuardos the standard as a first
I would say there is no "easy" tremolo piece. Tremolo is a special technique and when you can manage it then you can play most tremolo pieces and when you cannot manage it you cannot play any tremolo piece at all correctly.
But there is a little exception and warning. Playing tremolo on the first string is much more easier than on the second string. But beginning on the first string only might lead to bad habits which hinders you to play afterwards on the second string as needed e.g. at the Recuerdos (although some people play it on the first string which was not intended by F. Tarrega).
Thus I would indeed try to practice tremolo on both, the first and the second string. This means, try the practice routines always on the second string, too and do not limit yourself to an "easy" first string piece.
There is nothing more beautiful than the sound of a guitar - maybe aside from that of two guitars (Frederic Chopin)