since he have 3 start-up moves and based on pokemondb when you hatch riolu's egg, the first move he'll learn is his 3 start-up moves and then level-up moves and then egg-moves.
(i need him to learn vacuum wave and nasty plot at once, i want him to learn nasty plot earlier, it's annoying to wait until he leveled up to 47 to learn it)
It is pretty simple, Breed a Croagunk to have both Nasty Plot and Vacuum Wave, And Breed that specific Croagunk with a Female Lucario. This also works with Smeargle by the way.
Note: Both Pokemon must know Nasty Plot in order for this to work.
Uhh no Egg moves can replace the start up moves. Too breed Nasty-plot to him BOTH parents must have Nasty-plot, so you would have to have a female Lucario with Nasty-plot and (if you want Vacuum-wave) a Male Lucario with both Nasty-plot and Vacuum-wave or a Smeargle with Vacuum-wave and Nasty-plot. Smeargle is easier.
Hope I helped :)