At your rank, I would suggest this. Play all maps, and play every map. You're a very low rank and haven't been playing for very long, and that's okay, everyone started out at that rank. I did, you will, even the top players did. Nobody was a god from the start. Being a low rank, you just want to play as many beatmaps as you can, and get as much experience as you can. Don't replay maps, as this is the curse of every inconsistent player in the game. You won't be able to see it now, but inconsistency sadly starts to show very often at higher ranks. Also don't play mods, except hidden. Every new player seems to love doing this, but there's no real added benefit because the added difficulty is negligible. If the maps you play are becoming too was, don't play with mods, just play harder maps. Its far more beneficial in the long run. Hidden is an exception as it is used in almost every different mod combination in existence, and is also just a good mod to learn overall.
This is more important when you're around low (10k) 5 digit or 4 digit rankings but is still useful to knowThere's a key to learning and getting better at any skill, and thats self-evaluation. At your rank currently (1.6m), self-evaluation isn't going to do you much good because your skills aren't really developed to any major degree. Again, this is okay, everybody was there at some point. But as you get better and your start seeing your strengths and weaknesses (my strengths for example are jumping and reading, while my weaknesses are speed, fast streaming and high approach rates). This is a point where you'll want start self-evaluating and start refining your skills. I only just started now even though I'm mid 3 digits. Its all dependant on your best judgement call. Start looking at your weaknesses and do things to improve them. Lets just say though that your weakness is streaming. Don't just play solid stream maps that have no aim component to them at all. Find maps that challenge every aspect of skill, or most of them, but maybe focus most on streams, and train on those maps. That way you won't accidentally bottleneck yourself by training only one skill. Then, do it again. Re-evaluate yourself, and do it often. Get good at it. You'll find you'll get a lot better a lot faster when you train your weaknesses.
The last thing I'm going to say is to always challenge yourself, but know your limits. Sure you're rank 1.6m and could just play 6 stars all day, but that's not going to benefit you because 6 stars is way beyond your limit. Instead, find your comfort zone, and then move a little bit outside of it. Not too much at first, but as your skill level grows, you can challenge yourself more and go further outside your comfort zone.
So if I had to sum this up, it's a waste of time I could have spent doing school work. But seriously, my basic suggestion to you is this. Play every map you can, develop your skills, don't worry about mods until you're higher ranked, challenge yourself but not too much, eventually begin evaluating and refining your weaknesses, don't retry often, don't hurt yourself (learn the difference between pain and burning, burning is good, pain is not) and have fun. It's a game after all.