notespeed/song packs question

hi, im a player getting into arcaea, ive had it for a while but never was that interested; im coming back after pretty much quitting proseka. i have a 9.3 potential, lv17 tairitsu (i had characters sealed for a while oops), a couple future 8 fcs and AA clears on future 9 difficulties of goodtek/your voice so

i notice that a lot of good players are using minimum 4.5 note speed, but im sitting at like 3.4 and anything higher feels way too fast for me to comprehend usually? how do i get used to higher notespeeds + what even is a good notespeed to be sitting at (on proseka i use 10.2 and it feels like the same as arcaea 3.4 LOL)

also, any recs for song packs to buy? i am currently fully f2p but have heavily been considering buying, ive heard a lot of people recommend vicious labyrinth + i was also considering esoteric order for aegleseeker

ty!