The Spanish empire was so large that the sun was sure to be shining on at least one part of the empire at all times. It means that due to the sheer expanse of an empire, with territories in all corners of the globe, the sun was shining on at least one part of the empire.
Well, I can't completely help, but I do know some tricks.
For example, write it out fully in English, or the best language you have fluently, then put the whole essay into a translator. Next, make a new document, and copy and paste the translated version into it. Read it out many times, get some quick help (I know some podcasts that can help you learn Spanish easier, like Duolingo) and, once you have learned a bit more (another trick is to read through it using the translator, and see some of the translation parts to learn more Spanish from words that you used) filter out any kinks, and turn it in! It seems harder written out than it is, but it's an efficient way!
Hola, los nombres de mis gatos son Simba y Houdini