We know the depressing fate of John Doe who woke up one day in the Middle Ages, to quickly die or spend his life in a monastery.
His more lucky friend Mark had a vision before being transported and had time to prepare for that unusual trip.
He knew he would be sent near Versailles at the end of the 16th century (the time where Louis XIV moved the royal court there). He can take with him a robust 4x4 car (or other modern transport which can be handled by one person - be it a tank or a helicopter, but not an aircraft carrier), fit with whatever today's technology allows and filled to the brink with whatever he wants.
Mark wants to have fun when reaching Versailles but, while being somehow extrovert, he has pacifist intents. He will not be flying in with an Apache, killing everyone and announcing himself as Archangel Gabriel to take over France.
He just would like his stay there (planned for a month to a year) to be memorable and fun. He does not want to change history, but does not care that much about adding something to the facts or legends of Versailles (we can assume that, at most, he will be mentioned in history books, like Lully or other prominent people of that time, but not the ones who spontaneously pop up in your mind when thinking about the Versailles of Louis XIV).
- What kind of realistic dangers should he prepared for? (from the tourista to possibly some assassination attempts by Louis' BFF who feels threatened)
- What should he take with him to be the man of the party? (fireworks? a Rolling Stones grade audio system with XX an XXI century music? a laptop with a projector to show X-Men or Star Wars?)
- What are the goods he may be running out of by the end of his stay (~a few months) he should plan for? (power is the one which comes to my mind - maybe solar panels could be a viable alternative?)
He will be forcibly sent back to today at the end of his trip, together with everything he brought with him (and he will not bring back anything). He also has a clever panic button triggered by a specific sequence of eye and tongue mouvement which will send him back (under the same conditions). This is to avoid the cases where his trip becomes an opportunity for the king to change the world by torturing poor Mark into doing something which would trigger such a change.
Note: I am not sure about the science-based tag - I was looking for one which would say "no magic (beside the time-travel part), technology and science are at today's level". in other words, a well-prepared guy travels, today, ~350 years back.