The concept of time travel is largely speculative and theoretical, as no confirmed time-traveling technology currently exists. However, based on popular science fiction narratives and theories, I can provide some information.
In most fictional depictions of time travel, the idea of changing the future by altering the past is often explored. This concept is often associated with the "butterfly effect," which suggests that even minor changes in the past could have significant and unforeseen consequences in the future.
If we assume that changing the past can affect the future, then it follows that your future would not be fixed simply by observing it. By traveling back in time and making alterations, you could potentially create a different future from the one you initially witnessed or anticipated.
It's important to note that various time travel theories propose different mechanisms and rules, so the nature of time travel and its effects on the future can vary depending on the fictional or theoretical framework being considered. Ultimately, without a clear understanding of the actual nature of time and the possibilities of time travel, it remains a topic of speculation and imagination.