?............

if what I’ve seen in movies with time travel are real, ever changing

"Fate" is a word that is easily put in the extremes. Either stating it doesn't exist and that everything that happens to you is because you made it so, also meaning that getting in a bad life can only be your own fault, or stating that everything happening to you is decided by fate, or God or whatever.

Now nobody can decide their "fate" or "destiny", but one can try to influence it by the choices they make. The outcome is not always expected. However a lot of things are not in your control at all. Nobody decided to be born, nobody picked the country to be born in, nobody chose to be white or black or yellow or whatever, nobody chose to be a man or a woman from birth, etc. etc. Those things can be considered "fate"....

However just leaving everything to a set "fate" or "destiny" is not the right path to follow. We all face choices. Choices we can make ourselves, but a lot of stuff can turn out different. If you train to be a surgeon, but once you've completed your training there no hospital hiring you, then your choice didn't work out well, did it? Was it the wrong choice, or just bad luck? If you write books and nobody reads them, you fail as an author, but that doesn't mean your books are bad. Some very untalented authors had bestsellers after all. Yet, if you don't train to be a surgeon, you'll surely never be one. If you don't try to write books, you won't ever get your own bestseller. So just letting fate decide won't work. But sometimes fate doesn't allow to be decided, but still your influence could still get you somewhere. If you've trained to be a surgeon, but you can't find a job as a surgeon, but you discover some schools training doctors need teachers, hey perhaps your training can still come in handy....

In the end you should accept things never go the way you want, but in the same time you must also try to bend things a bit in your favor and hope for the best in doing so. Sometimes you must also accept that some things where never meant to be from the start. Every choice you make does cause a change... If it's the change you wanted, always remains to be seen.... But just because things didn't turn out the way you wanted doesn't mean you didn't cause a change.

I'm not sure if this all makes any sense, as I need more space to explain this more properly.

From what I can tell, it's set. Every action affects the next. If you don't follow that logic, then somehow you might instantaneously move from Dallas to Madrid. It's because of every action affecting the next that I think it wouldn't happen. If there was a simulation from the start of the universe to the end, it would probably look the same every time, if the exact beginning is always the same. If the variables don't change, then nothing changes.