There were cases of native Americans from British America and Brazil who traveled to Europe, though this is outside my field (Anthony Pagden has short discussions of this in European Encounters with the New World).
Unfortunately I'm not aware of any such indigenous accounts for colonial Spanish America. There's not that much information on the very first native Americans in Europe, and the focus tends to be much more on the first Europeans overseas. It's partly due to a focus on European authors and partly due to scarcity of sources - after all, native authors were very rarely published until the 19th c.

I've written on this here before, with more references:

• This one on probably the first people brought over: a small group of 7 Taíno brought in 1493 by Columbus to Spain "as proof of his findings". We don't know their own perspective unfortunately, but know that most of them returned to the Caribbean in order to aid in Christianization there.

• After this, large numbers of native slaves were forcibly brought to work in Spain from the early 16th c. This practice was outlawed in 1542 and eventually petered out by the 17th century. In addition, we know of some exceptional cases of native elites who went in diplomatic missions or live in Spain: incl. a descendant of the Aztec ruler Moctezuma, and a famous writer descended from the Inca (Inca Garcilaso de la Vega). In case you're interested, I've also written an answer on these later migrations.

Hope this helps!

Hi there - we're happy to approve your question related to your creative project, and we are happy for people to answer. However, we should warn you that many flairs have become reluctant to answer questions for aspiring novelists and the like, based on past experience: some people working on creative projects have a tendency to try to pump historians for trivia while ignoring the bigger points they were making, while others have a tendency to argue with historians when the historical reality does not line up with what's needed for a particular scene or characterization. Please respect the answers of people who have generously given you their time, even if it's not always what you want to hear.

Additionally, as amazing as our flair panel is, we should also point out that /r/AskHistorians is not a professional historical consultation service. If you're asking a question here because you need vital research for a future commercial product such as a historical novel, you may be better off engaging a historical consultant at a fair hourly rate to answer these questions for you. We don't know what the going rate for consultancy work would be in your locality, but it may be worth looking into that if you have in-depth or highly plot-reliant questions for this project. Some /r/AskHistorians flairs could be receptive to working as a consultant in this way. However, if you wish for a flair here to do this work for you, you will need to organize this with them yourselves.