I think it took me less than one week after discovering the concept of lucid dream and reading tutorial, before having my first LD.
Then it was intense practice, with dream journals (I even woke up with an alarm every sleep-cycle = 1h30 to write them... nights were not really resting then ), trying DILD and WILD, doing RC all day long... and it was quite productive, with a few LD every weeks.
You'll have more luck if you are very motivated (dreams and lucid dreams are driven by what obsess you in the day); and try different techniques, don't pick just one at random: everyone is different, and some techniques will suit you better than others.

Since a few years I stopped praticing "full time" (other interests, and not enough sleep to do proper LD, unfortunately) but the LD still occur occasionnaly.