Let's see, for 16th-century Spanish circumnavigations, I remember about 4 or 5 voyages. The most famous being the Magellan voyage (not to mention that is the first one known in history). Crew numbers, number of ships, and locations visited are all easily found online through generic searches. (a search for "List of circumnavigations" is easy enough)

All I can provide are pieces of generic information that is often pretty valid for the greater Age of Sail (but not necessarily specific to 16th-Century Spanish voyages). Based on the question, hopefully someone who is knowledgeable of Spanish maritime and/or Age of Exploration can help out with telling you about life during these voyages (that seems to be the topic of greatest potential in terms of not readily discoverable information online). The best book I know of about Spanish maritime activity in the 16th century (but not exploration, this is more ships going between the New World and Spain for transporting passengers and cargoes) is the book Spain's Men of the Sea: Daily Life on the Indies Fleets in the Sixteenth Century by Pablo E. Perez-Mallaina. I would suggest messaging someone on our "list of flaired users" to the right of the screen (under Resources) that has flair about Spain and/or Age of Exploration. Also, more specific sub questions of your four bracketed questions above might make others more willing to try and answer your questions (since one of the most discouraging things in AskHistorians are questions that are too broad or asking too many things and require way too much info to answer).