You have learned to cast spells. The information below details how you use those rules as a Drake-Blooded Warden.
Cantrips
You know two cantrips of your choice from the Sorcerer spell list (see that class's section for its list). Sorcerous Burst and True Strike are recommended. Whenever you gain a Warden level, you can replace one of these cantrips with another cantrip of your choice from the Sorcerer spell list.
When you reach Warden level 10, you learn another Sorcerer cantrip of your choice.
Spell Slots
The Drake-Blooded Spellcasting table shows how many spell slots you have to cast your level 1+ spells. You regain all expended slots when you finish a Long Rest.
Prepared Spells of Level 1+
You prepare the list of level 1+ spells that are available for you to cast with this feature. To start, choose three level 1 spells from the Sorcerer spell list. Burning Hands, Detect Magic, and Shield are recommended.
The number of spells on your list increases as you gain Warden levels, as shown in the Prepared Spells column of the Drake-Blooded Spellcasting table.
Whenever that number increases, choose additional spells from the Sorcerer spell list until the number of spells on your list matches the number on the table. The chosen spells must be of a level for which you have spell slots. For example, if you're a level 7 Warden, your list of prepared spells can include five Sorcerer spells of levels 1 and 2 in any combination.
Changing Your Prepared Spells
Whenever you gain a Warden level, you can replace one spell on your list with another Sorcerer spell for which you have spell slots.
Spellcasting Ability
Charisma is your spellcasting ability for your Sorcerer spells.
Spellcasting Focus
You can use an Arcane Focus as a Spellcasting Focus for your Sorcerer spells.