The magic bestowed on you by your deity grants you the ability to cast Spells. See chapter 10 in the PHB for the general rules of spellcasting and chapter 11 for the cleric spell list.

At 3rd level, you learn three cantrips, guidance and two others of your choice from the cleric spell list. At 10th level you learn one other cantrip of your choice from the cleric spell list.

Preparing and Casting Spells

The divine trickster table shows how many Spell Slots you have to cast your spells of 1st level and higher. To cast one of your divine trickster spells of 1st level or higher, you must expend a slot of the spell’s level or higher. You regain all expended Spell Slots when you finish a long rest.

You prepare the list of cleric spells that are available for you to cast, choosing from the cleric spell list. Each spell you choose must be from the enchantment, evocation, or illusion school of magic. When you prepare spells, choose a number of cleric spells from your possible schools of magic equal to your Wisdom modifier + 1/3 of your rogue level (minimum of 1 spell). The spells must be of a level for which you have spell slots.

Starting at 8th level, you can prepare 1 cleric spell from any school of magic, at 14th level you can prepare 2 cleric spells from any school of magic, and at 20th level, you can prepare 3 cleric spells from any school of magic.

You can change your list of prepared spells when you finish a long rest. Preparing a new list of cleric spells requires time spent in prayer and meditation: at least 1 minute per spell level for each spell on your list.