Get one of those training boards and keep repeating till you master it, the trick is to heat the board and you put solder and wire on it, not how most beginners go by heating the solder itself. Flux and other things are there as an aux to help in certain cases. I have been soldering since i was a kid (thanks dad for having the machine) and I use only two tips and some flux occasionally, nothing too crazy and don’t go obsessing over the details or the device brand or such.