Honestly, being a rising senior now, no way could I have a good topic by the time I entered sophomore year and probably not junior year. Before that, you have to know what your passions are (aka your peaks) and who you are… you get to tell the adcoms one thing about you during the app essentially. If I were you, go to notes on your phone, right down everything before highschool that was important in your life. If this becomes very important later down the road, it may be an essay, but the essay really should reflect who you are when you enter college, so its better to have a story that is in highschool. As you narrow down your ec’s/ add ec’s and gain new experiences, put those down on the notes. (I tried freshman and kinda sophomore year like speech and debate, Tedx, Model UN, DECA, Science Olympiad, Bio club, Investment club… what are adcoms gonna make of that if I stuck with those?). I think it’ll be much easier to get a topic for the essay once you streamline ec’s into your passions/ peaks. I believe that you should ultimately start drafting essays middle of junior year. If you want just for fun to do it summer before junior year then go for it, but its not the end of the world if you start August before apps are due (that’s when most colleges release their supplements…)