Q: Will I still have a functioning liver when I return from the timestream?
A: Probably not. You'll likely be a liverless husk of your former self. But hey, at least you'll have a great story to tell.
Q: Can I visit ancient Egypt and wear a fedora?
A: Only if you want to get trampled by an angry mob of pharaoh's guards. Leave the fedora at home, or at least wear a nice linen headdress.
Q: Will I be able to find any decent coffee in the year 3056?
A: Ha! Good luck with that. The coffee of the future is as bitter as the souls of the damned. Stick to the 1950s, when it was all about the diner cups.
How to Avoid Time Paradoxes