You don't need HR or DT yet, I'm 30k and play 90% of time nomod, I always played like that. Even doing a lot of Ar8 at this rank ('cause I'm used to old style beatmaps).
If you are better with HD it's good, though it works for good maps, the strange/old ones are quite hard to handle with HD. It feels easier for you because it's less distracting to the eye (no circle moving everywhere).
Their are ton of maps for your level honnestly, DT is not needed at the moment.
Good luck, even if I'm a bit younger than you I often feel the difference in the learning curve with children, but with training everything is possible.