you worry about the practical too much. all you need is the right phone booth or hot tub and its all take care of. .Time travel is even less likely than going faster than the speed of light. Some basically have you going back in time if you exceed the speed of light. I think Stephen Hawking had a party for time travelers once. He advertised the time and location after the party was over. He said no one showed up. Just way overused in the entertainment world. Leads to good stories but no way to actually do it. How do you really rewind time for the 2 trillion galaxies in the observable universe? Dark energy causes the expansion of the universe, do you somehow rewind it? What about your location relative to the universe, earth rotates around the sun, sun rotates around the galaxy, galaxy wanders through the universe, how do you fix it to a previous time? Going back in time also implies that the universe has a memory of what the previous state was. Where is that recorded? Anyway I could go on and on, but I really hate time travel as a possible concept, pretty much all legit science says it can't happen. You mind as well change the value of pi or the planck constant.
All fun stuff to think of but in reality today is today. in order for anyone to visit us, a very similar set of technical hurdles need to be conquered.
However just imagine of we were as we are now during the age of the dinosaurs. BBQs would be awsome and we would have millions of years of technological evolution under our belt. looking at cellphones and tvs today look like the jetsons cartoon from the 70s. all we need is flying cars the fold into a briefcase, . Fun topic.
We cant even capture Bigfoot. what is the likelyhood of capturing a UFO?