Know that gimping Lucario is not as easy as most people seem to think. We have a lovely wallcling option out of Extreme Speed, which is a pretty flexible recovery tool because of it's high level of controlability, and most Lucarios will counterpick a stage where this is possible. If he gets too far beneath the stage, however, he can be gimped in a pretty gay manner since Extreme Speed won't be able to travel enough distance and turn onto the stage as well (usually).
Side B will probably be useful for ya. A lot of Lucarios like their Fsmash a lot. It's got IASA frames and high range, but Side B has even longer. Mind that it doesn't become too stale, or Lucario will get really high % (170% is his cap) and aurape you. Lucarios also love their aura spheres
Lucario's a pretty versatile thingamajig. A lot of Lucarios will have different styles. I, personally, prefer the air (zomg), meaning I love to combo with Fair and go for gimps. He works offensively, defensively, balanced, gimp-happy, grab-happy, and campy as well. Watch your opponent and see if you can work out their pattern. Then punish it. Lucario is put in a awkward position when his Dair is shielded low to the ground. This isn't quite so easy for ZZS to punish because of her grab animation, which is the standard for punishing a shielded Dair. ZZS has great anti-air abilities though. Utilize 'em.