Like many of you I enjoy spending my free time evaluating theoretical particle physics and similar which often delves deep into "what if" territory. Out of all the ideas relating to time travel the one that's supported by the most evidence that comes out the cleanest in mathematical form is that quantum states in particles are responsible for "time" as we know it. The breakdown of which in a noobs guide to whatever subject you'd throw this under basically would say that all time is always happening simultaneously. Therefore a shift in quantum states of an array of particles could allow full on time travel without the need of any extra dimensions or universe .... universes? universai? w/e
To rephrase you could easily meet yourself in the past without any paradoxical consequences. Though I can't guarantee that you'll make it between points in one piece. The thing is the particles in you existed elsewhere in the past and while I'm inclined to believe that they'd stick with you in an altered state, there is the chance that you're triggering a reverse in the state and so all the particles would return to their original state in that time which wouldn't be pretty for you, and of course the other way around it's also possible that instead of existing in an altered state outright they'd converge on you from their locations in the past which wouldn't be pretty for the world.
Hopefully though minor things such as a few particles in different places wouldn't be too bad. Though if you're missing any in this state it's highly plausible you'd go completely insane. Things to consider anyway. So to reiterate there's at least 3 possible if not likely outcomes from quantum state based time travel. First particles in the past converge on you to make you. Second you exist as your comprised particles however only in the form of which they were in the past in their old locations which likely means you'd probably be dead or missing large chunks of your body. Third the particles from your present shift their state to that which is in alignment of an older time / younger depending on view and destination. The third option is the most likely in this case. That having been said you should reflect on the ideas presented then offer up a comment below.