It's all good! No worries I had my first lucid dream just the night after I got to know about it and then I didn't have any lucid dream for about 2 months.... So you might call my first lucid dream pure luck I guess.

You just need to find a nice routine that suits you. As long as you are consistent, keep up your practice and stay motivated, you will soon have more lucid dreams Noone can really tell you how long it takes. You just need to tell yourself that you can do it.
Have you got a dream journal? That's also really important to improve your dream recall and to analyse your dreams. You might also want to try WBTB and combine it with another technique that you like.

- Benni