What I have done so far: Mainly small tutorials, as long as I was writing the code myself, gaining muscle memory, I couldn't care less about how many tutorials I did. I have worked up to React and some simple Web3 React apps.
What would I do differently? I think that in order to find out if you enjoy something is to do it. Yeah, it may suck while you are doing it, however you will know at the end of the day that you don't like whatever it is you did. I used the same approach with programming languages. I could have 100 days of C, but I don't know about all of that.
My Advice: You don't want my advice, I am still level 1, maybe level 2 max.
Okay, Okay, Follow tutorials. But make sure you are the one typing it out, don’t copy and paste that shit. You will not learn anything that way. Write comments. Commenting in your code explains to yourself what you are doing. You will go back to “Project 1” and think, What!?! Find a passion and code that…
I'm kidding. I think that is a load of shit. You won't know what you are passionate about in the coding aspect until a while later, much less in the first 30 days. I say, sink your teeth into areas that interest you. Possibly you like X app, learn the tech behind it and check it out. Perhaps Machine Learning looks intriguing to you, check out TensorFlow or simply google “Machine Learning Languages”. The reason I say this is you might find you aren't that interested in something as you initially thought. I've done this “passion” thing and in the end, I wasn't very passionate about [insert here]. And finally, in terms of 100 days of code, have an outline. What do you plan to accomplish? How are you going to accomplish all you want to? I broke my outline up in thirty day increments. Pick a language. Build stupid, small things with said language. And the last thirty days, create a medium-sized project of my choice with ten days left to take my time on it as I see fit. All in all, it's your journey. Do what makes you happy.