Simple answers:
* Comí cereal con leche y fruta. (I ate cereal with milk and fruit.)
* Tomé un café y un sándwich. (I had coffee and a sandwich.)
* Desayuné huevos con tostadas. (I had eggs with toast.)
More detailed answers:
* Comí panqueques con jarabe de arce y fresas. (I ate pancakes with maple syrup and strawberries.)
* Tomé un smoothie de frutas con yogur y granola. (I had a fruit smoothie with yogurt and granola.)
* Desayuné un burrito de huevo con queso y salsa picante. (I had an egg burrito with cheese and hot sauce.)
If you didn't have breakfast:
* No desayuné hoy. (I didn't have breakfast today.)
* No tenía mucha hambre esta mañana. (I wasn't very hungry this morning.)
Remember to use the correct verb conjugation for the past tense of "desayunar" (to have breakfast).
Let me know if you have any other questions!