I'm going to assume the melee bit is not in regards to your Large ART bot.
The only L-Art you probably have right now is Destructor. Make sure to give him the 50% blast guard cart and then the red carts that boost his built in weaponry, which are his anti-air missiles. With the two attack carts his missiles step up to:
Default An enhanced Enhanced two
Power 21 22 23
Ammo 110 120 130
Range 370 370 380
Rate 160 170 170
Interval 2700 2600 2500
So as you can see, very important to get those attack carts, though the numbers seem less significant than they really are.
Generally speaking the LL Bazooka is not all that amazing, despite what its stats say.
You're better off with another missile launcher. Box missiles are pretty useful, but I forget which mode I got mine from.
You want to stay on or around the power spot and spam on any enemies who land in your sights, or find a somewhat decently high spot you can get to and sit there spamming your missiles. Going head first into battle with a desctructor is not the wisest of ideas, as ART is naturally vulnerable to melee damage more than other bots.
As for you Jinku, which is likely the only melee bot you have if you just made an CBJP account recently, I simply suggest you pick a melee wonder bit to go with him/her/it. You should go through quest mode (Arcantus) to collect Dual Slayer bits for this. Don't forget to use the drop 30% increase tickets from UC Garapon, as they are THETA tickets, and will last for a while, so you can farm drops longer.
