Pot qué decidiste estudiar el español? escribe por lo menos 5 oraciones an español

The first part of the question is asking why you decided to study spanish , so i think that is a personal question , but you could say for ex. " Yo decidi estudiar Español por que me parecio interesante " which means , " i decided to study spanish because it seemed interesting".
The second part is asking you for 5 sentences in Spanish , something like this ;
1. Melina corrio en el parque esta mañana. ( Melina ran in the park this morning)
2. Rossanna ama el algodon de azucar . ( Rossanna loves cottoncandy )
3. Cada dia , Blake se levanta a las 7 de la mañana. ( Everyday , Blake wakes up at 7 in the morning )
4. A mi me gusta ir a la playa en el verano. ( I like to go to the beach on summer)
5. Mi persona favorita vive en Texas. ( My favorite person lives in Texas)