You need to run Close Combat as it is the strongest and most reliable STAB move that Lucario has in his arsenal. Also Fighting moves do great in this meta against threats such as Kangaskhan, Terrakion, Hydreigon and Heatran to name a few.
Bullet Punch is for obvious priority and coverage against Fairy and Rock types.
Lucario is pretty frail so you will need Protect to shield him from attackers that OHKO or severely damage him.
Crunch allows you to hit Aegislash and is more reliable than Blaze Kick as it also hits Gengar, Cresselia,Jellicent and other Ghost and Psychic types used in the format. If you don't value Crunch's coverage as much then Ice Punch is also a good option as it hits Landorus, Thundurus, Salamence, Amoonguss, among other mons for super effective. Note that these mons resist or take little damage from Bullet Punch and Close Combat.
