Answer:
La semana pasada fue una semana muy ajetreada, ¡a pesar de que estuve de vacaciones! El lunes tuve que ir a la casa de mi hermana a cuidar a mis tres sobrinos, porque ella tenía que hacer unos mandados y la niñera estaba enferma. El martes limpié y ordené todo mi apartamento. Fue agotador pero ahora luce increíble. Valió la pena el esfuerzo. El miércoles ayudé a mi mamá a plantar muchas flores y plantas en su jardín, a ambas nos encanta la jardinería. El jueves cociné todo el día para una fiesta sorpresa que le organicé a mi mejor amiga y el sábado finalmente fue el día de la fiesta. Fue en la casa de sus padres, ella quedó encantada. ¡La torta que preparé fue un éxito!
Explanation:
Almost all the text is in the preterite, but some verbs are in the imperfect. This is really normal when talking about past events. The imperfect is used for situations that have certain continuity or that are somehow imprecise regarding when they started and finished. Another thing to take into consideration is that in Spanish days of the week aren't written in capital letters. It would be a mistake to write them that way.
Here's the text in English:
Last week was a really busy one, although I was on holidays! On Monday I had to go to my sister's house to take care of my three nephews because she needed to run some errands and the nanny was ill. On Tuesday I cleaned and ordered my whole apartment. It was exhausting but now it looks great. It was worth the effort. On Wednesday I helped my mom to plant some flowers and plants in her garden, we both love gardening. On Thursday I cooked all day for a surprise party I organized for my best friend and on Saturday finally we had the party on her parent's house, she was delighted! The cake I baked was a success!
