You're In Luck. There is a Latin American here in the forums.
Me!
K- Hola abuela.
R- Hola mi bebé.
R- ¿Te apetece pollo?
K- Lo siento, no soy carnívoro.
R- ¿Te pongo pastel? -=- Donde Pongo El Pastel? -=- Was the original question "Where do I put the cake?"
K- Sí, me encanta pastel!
R- ¿Te doy más pastel? -=- Le Gustaria mas pastel? -=- Would you like some more cake? The other one you put says "I give you more cake?"
K- Gracias, pero no puedo más.
R- Callete! Lo coma. -=- here you are saying "Shut Up, The Coma" if you want to say "Shut up and eat, or hush and eat. -=- Callate, y come.
K- Sí, te invito a la zarzuela esta noche con mi máma. ¿Puedes acompañarme?
R- Lo siento, necesito a cortar mi melena.
K- Yo desea que tú viene a las sierras mañana también. -=- I wish that you would come to the mountain ranges tomorrow as well" -=- Yo desea que tu vengas a las sierras manana tambien.
R- Sí, su plan está estupendo.
K- Gracias, adiós.
R- Adiós.
The ones that I haven't added a coment, or corrections are correct. So far you puntuation is really good, and use of accented vowels are great.
This really isn't spanish. It's more of Castellano, the language of spain.