Depends on the type of "time travel". Backwards time travel doesn't seem plausible, so I guess we're talking only about 1 way physical transport time travel. That kind of time travel is achieved either by traveling at speeds approaching the speed of light or via intense gravity, unless you consider something like being cryogenically frozen and then reanimated at some point in the future to be "time travel".

As far as least amount of impact? I guess in terms of impact, its best to travel to the nearest point in the future that you possibly can, so that hopefully very little has changed and you're still more or less the same person living the same life (with just a short gap from leaving the present and arriving in the future). Otherwise, you could take a huge risk and try to travel to the distant future to a time when all traces of your current life have disappeared and peoples' memory of you has long been forgotten.

You can't change the future (...of your original universe)

That die had already been cast, that wave function had already collapsed. The very act of traveling backwards immediately creates a new timeline no matter what.

Any change you make any step you take, is all affecting that new universe while your original universe keeps on keeping on the way that it was, except now without you in it.

So from your perspective, if you were to travel forward again, things would be different, yes. But only because you're no longer in your original universe. The people in your original universe would see no changes because in that universe, the wave function had already collapsed, the die had already been cast.

There is no chance to EVER get back to your original timeline no matter what. Every jump backwards instantly creates a new universe (one in which the wave function collapses to reveal that you have traveled through time) and every jump forward is in THAT new timeline.

Essentially, you can't go home again.

Well I travelled back in time and killed Hans-Johann Scherzlgruber-Vötzfenstein so the world wouldn't have to suffer through his atrocities.

Go outside the cabin, jerk off, go back.

Go back in time and meet Jesus while He was here on earth

Literally impossible to answer without discussing what type of time travel you mean.

Regardless, the cop out answer is that the time travel you do by existing is the least impactful. You are currently traveling forward through time merely by existing.