I think the best (and honest) way to do it is if you write the text in English and then try to translate it to Spanish. Then, you can show both versions to the community and ask for corrections. Otherwise, it could seem as if you wants someone do the main work for you.
I'm pretty sure if you do as I suggest, a lot of people will be delighted to help you, me included
(Don't apologize your Spanish. Our English isn't good, and we all are here for improving, and the only way to do it is being less afraid of making mistakes)