What you want to do is to summon as much Xyz monsters depending your situation/deck you're facing.
For example, if you duel a deck that relies much on monster destruction using spell/trap cards, you want to summon Constellar Omega.

If you have an offensive deck in front of you, summon Constellar Praesepe.

Some decks relies on one card to etablish all their strategies. In most cases, this card cannot be destroyed by cards effects. Constellar Pleiades goes through that limit since he sends back to the hand.

Finally,  to conclude the Xyz list, you have Constellar Ptolemy M7 ! This monster can send monsters back to the hand, no matter if they are on the field or in the Graveyard ! You can get back your cards that way and also, get rid of annoying opponent's monsters. On the plus side, Ptolemy is the strongest monster in the deck with 2700 ATK.

 

Constellar Sombrero must be used carefully ! Keep it as a Xyz material and detach it only on your turn when you have a summon left, that way, you will get his effect. It's also important to remember that you should think twice before summoning a monster. Don't start on a damage basis (except if you can knock your opponent life points to 0), but more on a summon focus basis. Overall, except level 5/6 monsters, Constellar monsters are not strong when alone on the field. Xyz as fast as possible.

 

As you noticed, Constellar monsters are a little weak. You want to boost them with card as Lumenize or Luminous Spark. You can even use Constellar Acubens, but be careful, it's kinda risky.

To defend, there are many cards. Some relies on the Xyz, others don't. Compulsory Evacuation Device directly comes to mind, BUT, you can also use Fairy Meteor Crush ! Just equip it to an opponent's monster and place a face down monster with low defense. Your opponent will be the one taking damage !

 

To fully master this deck, even if it's outdated, you must play it. That's just a basic guide of how to use the deck, there are many playstyles that only you can define. It's not a Link Format Deck, but it's fun !

IT'S TIME TO DUEL !!